KERAVISION INC /CA/
8-A12G, 1997-08-25
OPHTHALMIC GOODS
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<PAGE>
 
    As filed with the Securities and Exchange Commission on August 25, 1997

                                                       Total Number of Pages -
                                                   Index to Exhibits at Page -

                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  ___________

                                    FORM 8-A

               FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES
                    PURSUANT TO SECTION 12 (b) OR (g) OF THE
                        SECURITIES EXCHANGE ACT OF 1934

                                KERAVISION, INC.
             (Exact name of registrant as specified in its charter)

         DELAWARE                                       77-0328942
- ---------------------------------------                 ----------
(State of incorporation or organization)             (IRS Employer
                                                      Identification No.)
 
48630 MILMONT DRIVE, FREMONT, CA                       94538-7353
- ----------------------------------------               ----------
(Address of principal  executive offices)              (Zip Code)

 
 If this form relates to                     If this form relates to the
 the registration of a                       registration of a class of debt
 class of debt securities                    securities and is to become
 and is effective upon                       effective simultaneously with the
 filing pursuant to                          effectiveness of a concurrent
 General Instruction A(c)(1)                 registration statement under the
 please check the                            Securities Act of 1933 pursuant to
 following box.    [_]                       General Instruction A(c)(2) please
                                             check the following box.     [_]

       Securities to be registered pursuant to Section 12(b) of the Act:

     Title of each class                 Name of each exchange on which
     to be so registered                 each class is to be registered
     -------------------                 ------------------------------

         None                                 None
         ----                                 ----

       Securities to be registered pursuant to Section 12(g) of the Act:
<PAGE>
 
                        PREFERRED SHARE PURCHASE RIGHTS
                  -------------------------------------------
                               (Title of Class)

                                      -2-
<PAGE>
 
Item 1.        Description of Registrant's Securities to be Registered
               -------------------------------------------------------

     On August 18, 1997, the Board of Directors of KeraVision, Inc. (the
"Company") declared a dividend of one preferred share purchase right (a "Right")
for each outstanding share of Common Stock, $0.001 par value (the "Common
Shares"), of the Company.  The dividend is payable on September 8, 1997 (the
"Record Date") to stockholders of record as of the close of business on that
date.  Each Right entitles the registered holder to purchase from the Company
one one-thousandth of a share of Series A Participating Preferred Stock, $0.001
par value, of the Company (the "Preferred Shares"), subject to adjustment, at a
price of $60.00 per share, subject to adjustment (the "Purchase Price").  The
description and terms of the Rights are set forth in a Preferred Shares Rights
Agreement (the "Rights Agreement") dated as of August 18, 1997 between the
Company and BankBoston, N.A., as the Rights Agent (the "Rights Agent").

     The following is a general description only and is subject to the detailed
terms and conditions of the Rights Agreement.  A copy of the Rights Agreement,
including the Certificate of Designation, the form of Rights Certificate and the
Summary of Rights to be provided to stockholders of the Company, is attached as
Exhibit 4.1 to this Registration Statement and is incorporated herein by
reference.  All capitalized terms used herein, unless specifically defined
herein, have the meanings ascribed to them in the Rights Agreement.

Rights Evidenced by Common Share Certificates
- ---------------------------------------------

       The Rights will not be exercisable until the Distribution Date (defined
below).  Accordingly, Common Share certificates outstanding on the Record Date
will evidence the Rights related thereto, and Common Share certificates issued
after the Record Date will contain a notation incorporating the Rights Agreement
by reference.  Until the Distribution Date (or earlier redemption, exchange or
expiration of the Rights), the surrender or transfer of any certificates for
Common Shares, even without notation or a copy of the Summary of Rights being
attached thereto, will also constitute the transfer of the Rights associated
with the Common Shares represented by such certificate.

                                      -3-
<PAGE>
 
Distribution Date
- -----------------

       The Rights will separate from the Common Shares, certificates for the
Rights ("Rights Certificates") will be issued and the Rights will become
exercisable upon the earlier of: (i) the Close of Business on the tenth day (or
such later date as may be determined by action of a majority of Continuing
Directors then in office) after the Shares Acquisition Date (or, if the tenth
day after the Shares Acquisition Date occurs before the Record Date, the Close
of Business on the Record Date) or (ii) the Close of Business on the tenth day
(or such later date as may be determined by action of a majority of Continuing
Directors then in office) after the date that a tender or exchange offer by any
Person (other than the Company, any Subsidiary of the Company, any employee
benefit plan of the Company or of any Subsidiary of the Company, or any Person
or entity organized, appointed or established by the Company for or pursuant to
the terms of any such plan) is first published or sent or given within the
meaning of Rule 14d-2(a) of the General Rules and Regulations under the Exchange
Act, if, assuming the successful consummation thereof, such Person would be the
Beneficial Owner of 20% or more of the shares of Common Stock then outstanding.

Issuance of Rights Certificates, Expiration of Rights
- -----------------------------------------------------

       As soon as practicable following the Distribution Date, separate Rights
Certificates will be mailed to holders of record of the Common Shares as of the
close of business on the Distribution Date and such separate Rights Certificates
alone will evidence the Rights from and after the Distribution Date.  Unless
otherwise determined by the Board of Directors, all Common Shares issued prior
to the Distribution Date will be issued with Rights.  Common Shares issued after
the Distribution Date may be issued with Rights if such shares are issued
(i) upon the exercise, conversion or exchange of securities issued after
adoption of the Rights Agreement or (ii) pursuant to the exercise of stock
options or under any employee benefit plan or arrangement.  Except as otherwise
determined by the Board of Directors, no other Common Shares issued after the
Distribution Date will be issued with Rights.  In addition, no Common Shares
issued after the Distribution Date will be issued with Rights if such issuance
would result in (or create a signi-

                                      -4-
<PAGE>
 
ficant risk) (i) of material adverse tax consequences to the Company or the
person to whom such Rights Certificate would be issued or (ii) that such options
or plans would not qualify for otherwise available special tax treatment. The
Rights will expire on August 17, 2007 (the "Final Expiration Date"), unless the
Final Expiration Date is extended or unless the Rights are earlier redeemed or
exchanged by the Company or expire upon consummation of certain mergers,
consolidations or sales of assets, as described below.

Initial Exercise of the Rights
- -------------------------------

       Following the Distribution Date, and until the occurrence of one of the
subsequent events described below, holders of the Rights will be entitled to
receive, upon exercise and the payment of $60.00 (the "Purchase Price") per
Right, one one-thousandth of a Preferred Share.

Exchange Provision
- ------------------

       At any time after an Acquiring Person has become such and prior to the
Acquiring Person beneficially owning 15% or more of the outstanding Common
Shares, the Board of Directors of the Company may exchange the Rights (other
than Rights owned by the Acquiring Person or its affiliates), in whole or in
part, at an exchange ratio of one Common Share per Right (subject to
adjustment).

Right to Buy Common Shares at Half Price
- ----------------------------------------

       Unless the Rights are earlier redeemed or exchanged, in the event that an
Acquiring Person becomes such, other than pursuant to a tender offer which is
made for all of the outstanding Common Shares and approved by a majority of the
Continuing Directors after determining that the offer is both adequate and
otherwise in the best interests of the Company and its stockholders (a
"Permitted Offer"), then proper provision will be made so that each holder of a
Right which has not theretofore been exercised (other than Rights beneficially
owned by the Acquiring Person, which will thereafter be void) will thereafter
have the right to receive, upon exercise of a Right, a number of Common Shares
having a then current value equal to two times the Purchase Price.  In the event
that the Company does not have a sufficient number of Common Shares available,
or the Board decides that such action is necessary or appropriate and not
contrary to the interests of 

                                      -5-
<PAGE>
 
Rights holders, the Company may, among other things, instead substitute cash,
assets or other securities for the Common Shares into which the Rights would
have otherwise been exercisable.

Right to Buy Acquiring Company Stock at Half Price
- --------------------------------------------------

       Similarly, unless the Rights are earlier redeemed or exchanged, in the
event that, after the Shares Acquisition Date (as defined below), (i) the
Company consolidates with or merges into another entity, (ii) another entity
consolidates with or merges into the Company or (iii) the Company sells or
otherwise transfers 50% or more of its consolidated assets or earning power,
proper provision must be made so that each holder of a Right which has not
theretofore been exercised (other than Rights beneficially owned by the
Acquiring Person, which will thereafter be void) will thereafter have the right
to receive, upon exercise, a number of shares of common stock of the acquiring
company having a then current value equal to two times the Purchase Price
(unless the transaction satisfies certain conditions and is consummated with a
person who acquired shares pursuant to a Permitted Offer, in which case the
Rights will expire).


Adjustments to Prevent Dilution
- -------------------------------

       The Purchase Price payable, the number of Rights and the number of
Preferred Shares, Common Shares or other securities or property issuable upon
exercise of the Rights are subject to adjustment from time to time to prevent
dilution as set forth in the Rights Agreement.  With certain exceptions, no
adjustment in the Purchase Price will be required until cumulative adjustments
require an adjustment of at least 1% in such Purchase Price.

Rights and Preferences of the Preferred Shares
- ----------------------------------------------

     Preferred Shares purchasable upon exercise of the Rights will not be
redeemable.  Each Preferred Share will be entitled to an aggregate dividend of
1,000 times the dividend declared per Common Share.  In the event of
liquidation, the holders of the Preferred Shares will be entitled to a
preferential liquidation payment equal to accrued but unpaid dividends plus the
greater of $1,000 per share and 1,000 times the aggregate per share amount to be
distributed to the holders of Common Shares.  Each Preferred Share will have
1,000 votes, voting together with the holders of Common Shares, except as
required by law or the Certificate of Determination of Rights, 

                                      -6-
<PAGE>
 
Preferences and Privileges of Series A Participating Preferred Stock. In the
event of any merger, consolidation or other transaction in which Common Shares
are changed or exchanged, each Preferred Share will be entitled to receive 1,000
times the amount received per Common Share. These rights are protected by
customary anti-dilution provisions. Because of the nature of the dividend,
liquidation and voting rights of the Preferred Shares, the value of the one one-
thousandth interest in a Preferred Share purchasable upon exercise of each Right
should approximate the value of one Common Share.

Redemption
- ----------

       At any time prior to the close of business on the earlier of (i) the
tenth day following the date (the "Shares Acquisition Date") of public
announcement that an Acquiring Person has become such or such later date as may
be determined by a majority of the Continuing Directors and publicly announced
by the Company or (ii) the Final Expiration Date of the Rights, the Company may
redeem the Rights in whole, but not in part, at a price of $0.01 per Right
("Redemption Price").

No Stockholders' Rights Prior to Exercise
- -----------------------------------------

       Until a Right is exercised, the holder thereof, as such, will have no
rights as a shareholder of the Company (other than any rights resulting from
such holder's ownership of Common Shares), including, without limitation, the
right to vote or to receive dividends.

Amendment of Rights Agreement
- -----------------------------

       The provisions of the Rights Agreement may be supplemented or amended by
the Board of Directors in any manner prior to the Distribution Date without the
approval of Rights holders.  After the Distribution Date, the provisions of the
Rights Agreement may be supplemented or amended by the Board in order to
(i) cure any ambiguity, defect or inconsistency, (ii) to make changes which are
deemed necessary or advisable and do not adversely affect the interests of
holders of Rights (excluding the interests of any Acquiring Person), or to
shorten or lengthen any time period under the Rights Agreement; provided,
however, that no amendment to lengthen (A) the time period governing redemption
shall be made at such time as the Rights are not 

                                      -7-
<PAGE>
 
redeemable, or (B) any other period unless for the purpose of protecting,
enhancing or clarifying the rights of, and/or benefits to, the holders of
Rights.

Certain Anti-takeover Effects
- -----------------------------

       The Rights approved by the Board are designed to protect and maximize the
value of the outstanding equity interests in the Company in the event of an
unsolicited attempt by an acquiror to take over the Company, in a manner or on
terms not approved by the Board of Directors.  Takeover attempts frequently
include coercive tactics to deprive a corporation's Board of Directors and its
stockholders of any real opportunity to determine the destiny of the
corporation.  The Rights have been declared by the Board in order to deter such
tactics, including a gradual accumulation of shares in the open market of a 20%
or greater position to be followed by a merger or a partial or two-tier tender
offer that does not treat all stockholders equally.  These tactics unfairly
pressure stockholders, squeeze them out of their investment without giving them
any real choice and deprive them of the full value of their shares.

     The Rights are not intended to prevent a takeover of the Company.  The
Rights are not exercisable in the event of a Permitted Offer, as described
above.  The Rights may be redeemed by the Company at $0.01 Right within ten days
(or such later date as may be determined by a majority of the Continuing
Directors) after the accumulation of 20% or more of the Company's outstanding
Common Shares by a single acquiror or group.  Accordingly, the Rights should not
preclude any merger or business combination approved by the Board of Directors.
Issuance of the Rights does not in any way weaken the financial strength of the
Company or interfere with its business plans. The issuance of the Rights has no
immediate dilutive effect, will not affect reported earnings per share, should
not be taxable to the Company or to its stockholders and will not change the way
in which the Company's shares are presently traded.  The Company's Board of
Directors believes that the Rights represent a sound and reasonable means of
addressing the complex issues of corporate policy created by the current
takeover environment.  However, the Rights may have the effect of rendering more
difficult or discouraging an acquisition of the Company deemed undesirable by
the Board of Directors.  The Rights may cause substantial 

                                      -8-
<PAGE>
 
dilution to a person or group that attempts to acquire the Company on terms or
in a manner not approved by the Company's Board of Directors, except pursuant to
an offer conditioned upon the negation, purchase or redemption of the Rights.

Item 2.   Exhibits.
- -------   ---------

             3.5       Amended and Restated Bylaws of KeraVision, Inc.

             4.1       Preferred Shares Rights Agreement, dated as of August 18,
                       1997, between KeraVision, Inc. and BankBoston, N.A.,
                       including the Certificate of Designation of Rights,
                       Preferences and Privileges of Series A Participating
                       Preferred Stock, the form of Rights Certificate and the
                       Summary of Rights attached thereto as Exhibits A, B and
                       C, respectively.

            10.22      Form of Change of Control Agreement dated as of May 6,
                       1997 between KeraVision, Inc. and each of Darlene E.
                       Crockett-Billig, Mark D. Fischer-Colbrie, Edward R.
                       Newill, Patrick Sabaria, Thomas A. Silvestrini and Robert
                       P. Wood.

            10.23      Change of Control Agreement dated as of May 6, 1997
                       between KeraVision, Inc. and Thomas M. Loarie.

                                      -9-
<PAGE>
 
                                   SIGNATURE

     Pursuant to the requirements of Section 12 of the Securities Exchange Act
of 1934, the Registrant has duly caused this Registration Statement to be signed
on its behalf by the undersigned, thereto duly authorized.

Date: August 25, 1997                    KERAVISION, INC.


                                By: /s/Thomas M. Loarie
                                    ----------------------------------------
                                    THOMAS M. LOARIE,
                                    PRESIDENT AND CHIEF EXECUTIVE OFFICER

                                      -10-
<PAGE>
 
                               INDEX TO EXHIBITS

                                                                   Sequentially
                                                                   ------------
        Exhibit No.          Description                           Numbered Page
        -----------          -----------                           -------------

 
 
            3.5              Amended and Restated Bylaws of
                             KeraVision, Inc.

            4.1              Preferred Shares Rights Agreement,
                             dated as of August 18, 1997, between
                             KeraVision, Inc. and BankBoston,
                             N.A., including the Certificate of
                             Designation of Rights, Preferences
                             and Privileges of Series A
                             Participating Preferred Stock, the
                             form of Rights Certificate and the
                             Summary of Rights attached thereto
                             as Exhibits A, B and C,
                             respectively.

           10.22             Form of Change of Control Agreement
                             dated as of May 6, 1997 between
                             KeraVision, Inc. and each of
                             Darlene E. Crockett-Billig, Mark D.
                             Fischer-Colbrie, Edward R. Newill,
                             Patrick Sabaria, Thomas A.
                             Silvestrini and Robert P. Wood.
 
          10.23              Change of Control Agreement dated
                             as of May 6, 1997 between
                             KeraVision, Inc. and Thomas M.
                             Loarie.

<PAGE>
 
                                                                     EXHIBIT 3.5
 
                           AMENDED AND RESTATED BYLAWS

                                       OF

                                KERAVISION, INC.

                                    ARTICLE I


                                CORPORATE OFFICES
                                -----------------

         1.1      REGISTERED OFFICE
                  -----------------

         The registered office of the corporation shall be in the City of
Wilmington, County of New Castle, State of Delaware. The name of the registered
agent of the corporation at such location is The Corporation Trust Company.

         1.2      OTHER OFFICES
                  -------------

         The board of directors may at any time establish other offices at any
place or places where the corporation is qualified to do business.

                                   ARTICLE II

                            MEETINGS OF STOCKHOLDERS
                            ------------------------

         2.1      PLACE OF MEETINGS
                  -----------------

         Meetings of stockholders shall be held at any place, within or outside
the State of Delaware, designated by the board of directors. In the absence of
any such designation, stockholders' meetings shall be held at the registered
office of the corporation.

         2.2      ANNUAL MEETING
                  --------------

         The annual meeting of stockholders shall be held each year on a date
and at a time designated by the board of directors. At the meeting, directors
shall be elected and any other proper business may be transacted.

         2.3      SPECIAL MEETING
                  ---------------

         A special meeting of the stockholders may be called at any time by the
board of directors, or by the chairman of the board, or by the chief executive
officer or the president or vice president of the corporation.
<PAGE>
 
         2.4      NOTICE OF STOCKHOLDERS' MEETINGS
                  --------------------------------

         All notices of meetings with stockholders shall be in writing and shall
be sent or otherwise given in accordance with Section 2.5 of these Bylaws not
less than ten (10) nor more than sixty (60) days before the date of the meeting
to each stockholder entitled to vote at such meeting. The notice shall specify
the place, date and hour of the meeting, and, in the case of a special meeting,
the purpose or purposes for which the meeting is called.

         2.5      ADVANCE NOTICE OF STOCKHOLDER NOMINEES
                  --------------------------------------

         Only persons who are nominated in accordance with the procedures set
forth in this Section 2.5 shall be eligible for election as directors.
Nominations of persons for election to the board of directors of the corporation
may be made at a meeting of stockholders by or at the direction of the board of
directors or by any stockholder of the corporation entitled to vote for the
election of directors at the meeting who complies with the notice procedures set
forth in this Section 2.5. Such nominations, other than those made by or at the
direction of the board of directors, shall be made pursuant to timely notice in
writing to the secretary of the corporation.

         To be timely, a stockholder's notice shall be delivered to or mailed
and received at the principal executive offices of the corporation (a) in the
case of an annual meeting, not less than sixty (60) days nor more than ninety
(90) days prior to the first anniversary of the preceding year's annual meeting;
provided, however, that in the event that the date of the annual meeting is
changed by more than thirty (30) days from such anniversary date, notice by the
stockholders to be timely must be so received not later then the close of
business on the tenth (10th) day following the earlier of the day on which such
notice of the date of the meeting was mailed or public disclosure was made and
(b) in the case of a special meeting at which directors are to be elected, not
later than the close of business on the tenth (10th) day following the earlier
of the day on which notice of the date of the meeting was mailed or public
disclosure was made. Such stockholder's notice shall set forth (a) as to each
person whom the stockholder proposes to nominate for election or re-election as
a director, (i) the name, age, business address and residence address of such
person, (ii) the principal occupation or employment of such person, (iii) the
class and number of shares of the corporation which are beneficially owned by
such person and (iv) any other information relating to such person that is
required to be disclosed in solicitations of proxies for election of directors,
or is otherwise required, in each case pursuant to Regulation 14A under the
Securities Exchange Act of 1934, as amended (including, without limitation, such
person's written consent to being named in the proxy statement as a nominee and
to serving as a director if elected); and (b) as to the stockholder giving the
notice (i) the name and address, as they appear on the corporation's books, of
such stockholder and (ii) the class and number of shares of the corporation
which are beneficially owned by such stockholder and also which are owned of
record by such stockholder.

         At the request of the board of directors any person nominated by the
board of directors for election as a director shall furnish to the secretary of
the corporation that information required to be set forth in a stockholder's
notice of nomination which pertains to the nominee. No person shall be eligible
for election as a director of the corporation unless nominated in accordance
with 
<PAGE>
 
the procedures set forth in this Section 2.5. The chairman of the meeting
shall, if the facts warrant, determine and declare to the meeting that a
nomination was not made in accordance with the procedures prescribed by the
Bylaws, and if he or she should so determine, he or she shall so declare to the
meeting and the defective nomination shall be disregarded. Notwithstanding the
foregoing provisions of this Bylaw, a stockholder shall also comply with all
applicable requirements of the Securities Exchange Act of 1934, as amended, and
the rules and regulations thereunder with respect to the matters set forth in
this Bylaw.

         2.6      ADVANCE NOTICE OF STOCKHOLDER BUSINESS
                  --------------------------------------

         At an annual meeting of the stockholders, only such business shall be
conducted as shall have been properly brought before the annual meeting. To be
properly brought before an annual meeting, business must be: (a) pursuant to the
corporation's notice of meeting (or any supplement thereto), (b) by or at the
direction of the Board of Directors, or (c) by any stockholder of the
corporation who is a stockholder of record at the time of giving of the notice
provided for in this Section 2.6, who shall be entitled to vote at such meeting
and who complies with the notice procedures set forth in this Section 2.6.

         Business to be brought before an annual meeting by a stockholder shall
not be considered properly brought if the stockholder has not given timely
notice thereof in writing to the secretary of the corporation. To be timely, a
stockholder's notice must be delivered to or mailed and received at the
principal executive offices of the corporation not less than sixty (60) nor more
than ninety (90) days prior to the first anniversary of the preceding year's
annual meeting; provided, however, that in the event that the date of the
meeting is changed by more than thirty (30) days from such anniversary date,
notice by the stockholder to be timely must be so received not later than the
close of business on the tenth (10th) day following the earlier of the day on
which such notice of the date of the meeting was mailed or such public
disclosure was made. A stockholder's notice to the secretary shall set forth as
to each matter the stockholder proposes to bring before the meeting: (i) a brief
description of the business desired to be brought before the meeting and the
reasons for conducting such business at the meeting, (ii) the name and address,
as they appear on the corporation's books, of the stockholder proposing such
business, and the name and address of the beneficial owner, if any, on whose
behalf the proposal is made, (iii) the class and number of shares of the
corporation, which are owned by the stockholder of record and by the beneficial
owner, if any, on whose behalf the proposal is made, (iv) any material interest
of the stockholder of record and the beneficial owner, if any, on whose behalf
the proposal is made in such business, and (v) any other information that is
required by law to be provided by the stockholder in his or her capacity as a
proponent of a stockholder proposal.

         Notwithstanding anything in these bylaws to the contrary, no business
shall be conducted at an annual meeting except in accordance with the procedures
set forth in this Section 2.6. The chairman of the meeting shall, if the facts
warrant, determine and declare at the meeting that business was not properly
brought before the meeting in accordance with the provisions of this Section,
and, if he or she should so determine, he 
<PAGE>
 
or she shall so declare at the meeting that any such business not properly
brought before the meeting shall not be transacted. Notwithstanding the
foregoing provisions of this Bylaw, a stockholder shall also comply with all
applicable requirements of the Securities Exchange Act of 1934, as amended, and
the rules and regulations thereunder with respect to the matters set forth in
this Bylaw.

         2.7      MANNER OF GIVING NOTICE; AFFIDAVIT OF NOTICE
                  --------------------------------------------

         Written notice of any meeting of stockholders, if mailed, is given when
deposited in the United States mail, postage prepaid, directed to the
stockholder at his or her address as it appears on the records of the
corporation. An affidavit of the secretary or an assistant secretary or of the
transfer agent of the corporation that the notice has been given shall, in the
absence of fraud, be prima facie evidence of the facts stated therein.

         2.8      QUORUM
                  ------

         The holders of a majority of the stock issued and outstanding and
entitled to vote thereat, present in person or represented by proxy, shall
constitute a quorum at all meetings of the stockholders for the transaction of
business except as otherwise provided by statute or by the certificate of
incorporation. If, however, such quorum is not present or represented at any
meeting of the stockholders, then either (i) the Chairman of the meeting or (ii)
the stockholders entitled to vote thereat, present in person or represented by
proxy, shall have power to adjourn the meeting from time to time, without notice
other than announcement at the meeting, until a quorum is present or
represented. At such adjourned meeting at which a quorum is present or
represented, any business may be transacted that might have been transacted at
the meeting as originally noticed.

         2.9      ADJOURNED MEETING; NOTICE
                  -------------------------

         When a meeting is adjourned to another time or place, unless these
Bylaws otherwise require, notice need not be given of the adjourned meeting if
the time and place thereof are announced at the meeting at which the adjournment
is taken. At the adjourned meeting the corporation may transact any business
that might have been transacted at the original meeting. If the adjournment is
for more than thirty (30) days, or if after the adjournment a new record date is
fixed for the adjourned meeting, a notice of the adjourned meeting shall be
given to each stockholder of record entitled to vote at the meeting.

         2.10     CONDUCT OF BUSINESS
                  -------------------

         The Chairman of any meeting of stockholders shall determine the order
of business and the procedure at the meeting, including such regulation of the
manner of voting and the conduct of business.
<PAGE>
 
         2.11     VOTING
                  ------

         The stockholders entitled to vote at any meeting of stockholders shall
be determined in accordance with the provisions of Section 2.14 of these Bylaws,
subject to the provisions of Sections 217 and 218 of the General Corporation Law
of Delaware (relating to voting rights of fiduciaries, pledgors and joint owners
of stock and to voting trusts and other voting agreements).

         Except as may be otherwise provided in the certificate of
incorporation, each stockholder shall be entitled to one vote for each share of
capital stock held by such stockholder.

         2.12     WAIVER OF NOTICE
                  ----------------

         Whenever notice is required to be given under any provision of the
General Corporation Law of Delaware or of the certificate of incorporation or
these Bylaws, a written waiver thereof, signed by the person entitled to notice,
whether before or after the time stated therein, shall be deemed equivalent to
notice. Attendance of a person at a meeting shall constitute a waiver of notice
of such meeting, except when the person attends a meeting for the express
purpose of objecting, at the beginning of the meeting, to the transaction of any
business because the meeting is not lawfully called or convened. Neither the
business to be transacted at, nor the purpose of, any regular or special meeting
of the stockholders need be specified in any written waiver of notice unless so
required by the certificate of incorporation or these Bylaws.

         2.13     NO STOCKHOLDER ACTION BY WRITTEN CONSENT WITHOUT A MEETING
                  ----------------------------------------------------------

         Any action required to be taken or which may be taken at annual or
special meeting of stockholders of the corporation, must be taken at an annual
or special meeting of stockholders of the corporation, with prior notice and
with a vote, and may not be taken by a consent in writing.

         2.14     RECORD DATE FOR STOCKHOLDER NOTICE; VOTING
                  ------------------------------------------

         In order that the corporation may determine the stockholders entitled
to notice of or to vote at any meeting of stockholders or any adjournment
thereof, or entitled to receive any payment of any dividend or other
distribution or allotment of any rights, or entitled to exercise any rights in
respect of any change, conversion or exchange of stock or for the purpose of any
other lawful action, the board of directors may fix, in advance, a record date,
which shall not be more than sixty (60) nor less than ten (10) days before the
date of such meeting, nor more than sixty (60) days prior to any other action.

         If the board of directors does not so fix a record date:

                  (i) The record date for determining stockholders entitled to
notice of or to vote at a meeting of stockholders shall be at the close of
business on the day next preceding the day on which notice is given, or, if
notice is waived, at the close of business on the day next preceding the day on
which the meeting is held.
<PAGE>
 
                  (ii) The record date for determining stockholders for any
other purpose shall be at the close of business on the day on which the board of
directors adopts the resolution relating thereto.8

         A determination of stockholders of record entitled to notice of or to
vote at a meeting of stockholders shall apply to any adjournment of the meeting;
provided, however, that the board of directors may fix a record date for the
adjourned meeting.

         2.14     PROXIES
                  -------

         Each stockholder entitled to vote at a meeting of stockholders or to
express consent or dissent to corporate action in writing without a meeting may
authorize another person or persons to act for him by a written proxy, signed by
the stockholder and filed with the secretary of the corporation, but no such
proxy shall be voted or acted upon after three (3) years from its date, unless
the proxy provides for a longer period. A proxy shall be deemed signed if the
stockholder's name is placed on the proxy (whether by manual signature,
typewriting, telegraphic transmission or otherwise) by the stockholder or the
stockholder's attorney-in-fact. The revocability of a proxy that states on its
face that it is irrevocable shall be governed by the provisions of Section
212(c) of the General Corporation Law of Delaware.

                                   ARTICLE III

                                    DIRECTORS
                                    ---------

         3.1      POWERS
                  ------

         Subject to the provisions of the General Corporation Law of Delaware
and any limitations in the certificate of incorporation or these Bylaws relating
to action required to be approved by the stockholders or by the outstanding
shares, the business and affairs of the corporation shall be managed and all
corporate powers shall be exercised by or under the direction of the Board of
Directors.

         3.2      NUMBER OF DIRECTORS
                  -------------------

         The Board of Directors shall consist of seven (7) persons until changed
by a proper amendment of this Section 3.2.

         No reduction of the authorized number of directors shall have the
effect of removing any director before that director's term of office expires.
<PAGE>
 
         3.3      ELECTION, QUALIFICATION AND TERM OF OFFICE OF DIRECTOR
                  ------------------------------------------------------

         The board of directors shall be divided into three classes, as nearly
equal in number as possible. The term of office of the first class shall expire
at the 1996 annual meeting of stockholders or any special meeting in lieu
thereof, the term of office of the second class shall expire at the 1997 annual
meeting of stockholders or any special meeting in lieu thereof and the term of
office of the third class shall expire at the 1998 annual meeting of
stockholders or any special meeting in lieu thereof. At each annual meeting of
stockholders or special meeting in lieu thereof following such initial
classification, directors elected to succeed those directors whose terms expire
shall be elected for a term of office to expire at the third succeeding annual
meeting of stockholders or special meeting in lieu thereof after their election
and until their successors are duly elected and qualified. The foregoing
provisions shall become effective only when the corporation becomes a listed
corporation within the meaning of Section 301.5 of the California Corporations
Code. Directors need not be stockholders unless so required by the certificate
of incorporation or these Bylaws, wherein other qualifications for directors may
be prescribed.

         Subject to the rights of the holders of any series of Preferred Stock
then outstanding, newly created directorships resulting from any increase in the
authorized number of directors or any vacancies in the Board of Directors
resulting from death, resignation, retirement, disqualification, removal from
office or other cause may be filled only by a majority vote of the directors
then in office even though less than a quorum, or by a sole remaining director.
In the event of any increase or decrease in the authorized number of directors,
(i) each director then serving as such shall nevertheless continue as a director
of the class of which he or she is a member until the expiration of his or her
current term or his or her prior death, retirement, removal or resignation and
(ii) the newly created or eliminated directorships resulting from such increase
or decrease shall if reasonably possible be apportioned by the Board of
Directors among the three classes of directors so as to ensure that no one class
has more than one director more than any other class. To the extent reasonably
possible, consistent with the foregoing rule, any newly created directorships
shall be added to those classes whose terms of office are to expire at the
latest dates following such allocation and newly eliminated directorships shall
be subtracted from those classes whose terms of office are to expire at the
earliest dates following such allocation, unless otherwise provided for from
time to time by resolution adopted by a majority of the directors then in
office, although less than a quorum. In the event of a vacancy in the Board of
Directors, the remaining directors, except as otherwise provided by law, may
exercise the powers of the full Board of Directors until the vacancy is filled.
Notwithstanding the foregoing, each director shall serve until his or her
successor is duly elected and qualified or until his or her death, resignation,
or removal. No decrease in the number of directors constituting the Board of
Directors shall shorten the term of any incumbent director.

         Elections of directors need not be by written ballot.

         There shall be no right with respect to shares of stock of the
corporation to cumulate votes in the election of directors.
<PAGE>
 
         3.4      PLACE OF MEETINGS; MEETINGS BY TELEPHONE
                  ----------------------------------------

         The Board of Directors of the corporation may hold meetings, both
regular and special, either within or outside the State of Delaware.

         Unless otherwise restricted by the certificate of incorporation or
these Bylaws, members of the Board of Directors, or any committee designated by
the Board of Directors, may participate in a meeting of the Board of Directors,
or any committee, by means of conference telephone or similar communications
equipment by means of which all persons participating in the meeting can hear
each other, and such participation in a meeting shall constitute presence in
person at the meeting.

         3.5      REGULAR MEETINGS
                  ----------------

         Regular meetings of the Board of Directors may be held without notice
at such time and at such place as shall from time to time be determined by the
board.

         3.6      SPECIAL MEETINGS; NOTICE
                  ------------------------

         Special meetings of the Board of Directors for any purpose or purposes
may be called at any time by the chairman of the board, the president, any vice
president, the secretary or any two (2) directors.

         Notice of the time and place of special meetings shall be delivered
personally or by telephone to each director or sent by first-class mail or
telegram, charges prepaid, addressed to each director at that director's address
as it is shown on the records of the corporation. If the notice is mailed, it
shall be deposited in the United States mail at least four (4) days before the
time of the holding of the meeting. If the notice is delivered personally or by
telephone or by telegram, it shall be delivered personally or by telephone or to
the telegraph company at least forty-eight (48) hours before the time of the
holding of the meeting. Any oral notice given personally or by telephone may be
communicated either to the director or to a person at the office of the director
who the person giving the notice has reason to believe will promptly communicate
it to the director. The notice need not specify the purpose or the place of the
meeting, if the meeting is to be held at the principal executive office of the
corporation.

         3.7      QUORUM
                  ------

         At all meetings of the Board of Directors, a majority of the authorized
number of directors shall constitute a quorum for the transaction of business
and the act of a majority of the directors present at any meeting at which there
is a quorum shall be the act of the Board of Directors, except as may be
otherwise specifically provided by statute or by the certificate of
incorporation. If a quorum is not present at any meeting of the Board of
Directors, then the directors present thereat may adjourn the meeting from time
to time, without notice other than announcement at the meeting, until a quorum
is present.
<PAGE>
 
         A meeting at which a quorum is initially present may continue to
transact business notwithstanding the withdrawal of directors, if any action
taken is approved by at least a majority of the required quorum for that
meeting.

         3.8      WAIVER OF NOTICE
                  ----------------

         Whenever notice is required to be given under any provision of the
General Corporation Law of Delaware or of the certificate of incorporation or
these Bylaws, a written waiver thereof, signed by the person entitled to notice,
whether before or after the time stated therein, shall be deemed equivalent to
notice. Attendance of a person at a meeting shall constitute a waiver of notice
of such meeting, except when the person attends a meeting for the express
purpose of objecting, at the beginning of the meeting, to the transaction of any
business because the meeting is not lawfully called or convened. Neither the
business to be transacted at, nor the purpose of, any regular or special meeting
of the directors, or members of a committee of directors, need be specified in
any written waiver of notice unless so required by the certificate of
incorporation or these Bylaws.

         3.9      BOARD ACTION BY WRITTEN CONSENT WITHOUT A MEETING
                  -------------------------------------------------

         Unless otherwise restricted by the certificate of incorporation or
these Bylaws, any action required or permitted to be taken at any meeting of the
Board of Directors, or of any committee thereof, may be taken without a meeting
if all members of the board or committee, as the case may be, consent thereto in
writing and the writing or writings are filed with the minutes of proceedings of
the board or committee. Written consents representing actions taken by the board
or committee may be executed by telex, telecopy or other facsimile transmission,
and such facsimile shall be valid and binding to the same extent as if it were
an original.

         3.10     FEES AND COMPENSATION OF DIRECTORS
                  ----------------------------------

         Unless otherwise restricted by the certificate of incorporation or
these Bylaws, the Board of Directors shall have the authority to fix the
compensation of directors. No such compensation shall preclude any director from
serving the corporation in any other capacity and receiving compensation
therefor.

         3.11     APPROVAL OF LOANS TO OFFICERS
                  -----------------------------

         The corporation may lend money to, or guarantee any obligation of, or
otherwise assist any officer or other employee of the corporation or of its
subsidiary, including any officer or employee who is a director of the
corporation or its subsidiary, whenever, in the judgment of the directors, such
loan, guaranty or assistance may reasonably be expected to benefit the
corporation. The loan, guaranty or other assistance may be with or without
interest and may be unsecured, or secured in such manner as the Board of
Directors shall approve, including, without limitation, a pledge of shares of
stock of the corporation. Nothing contained in this section shall be deemed to
deny, limit or restrict the powers of guaranty or warranty of the corporation at
common law or under any statute.
<PAGE>
 
         3.12     REMOVAL OF DIRECTORS
                  --------------------

         The holders of a majority of the shares then entitled to vote at an
election of directors may remove, only with cause, a director or directors of
the corporation.

         No reduction in the authorized number of directors shall have the
effect of removing any director prior to the expiration of such director's term
of office.

         3.13     CHAIRMAN OF THE BOARD OF DIRECTORS
                  ----------------------------------

         The corporation may also have, at the discretion of the Board of
Directors, a chairman of the Board of Directors who shall not be considered an
officer of the corporation.

                                   ARTICLE IV

                                   COMMITTEES
                                   ----------

         4.1      COMMITTEES OF DIRECTORS
                  -----------------------

         The Board of Directors may, by resolution passed by a majority of the
whole board, designate one or more committees, with each committee to consist of
one or more of the directors of the corporation. The board may designate one or
more directors as alternate members of any committee, who may replace any absent
or disqualified member at any meeting of the committee. In the absence or
disqualification of a member of a committee, the member or members thereof
present at any meeting and not disqualified from voting, whether or not he, she
or they constitute a quorum, may unanimously appoint another member of the Board
of Directors to act at the meeting in the place of any such absent or
disqualified member. Any such committee, to the extent provided in the
resolution of the Board of Directors or in the Bylaws of the corporation, shall
have and may exercise all the powers and authority of the Board of Directors in
the management of the business and affairs of the corporation, and may authorize
the seal of the corporation to be affixed to all papers that may require it; but
no such committee shall have the power or authority to (i) amend the certificate
of incorporation (except that a committee may, to the extent authorized in the
resolution or resolutions providing for the issuance of shares of stock adopted
by the Board of Directors as provided in Section 151(a) of the General
Corporation Law of Delaware, fix the designations and any of the preferences or
rights of such shares relating to dividends, redemption, dissolution, any
distribution of assets of the corporation or the conversion into, or the
exchange of such shares for, shares of any other class or classes or any other
series of the same or any other class or classes of stock of the corporation or
fix the number of shares of any series of stock or authorize the increase or
decrease of the shares of any series), (ii) adopt an agreement of merger or
consolidation under Sections 251 or 252 of the General Corporation Law of
Delaware, (iii) recommend to the stockholders the sale, lease or exchange of all
or substantially all of the corporation's property and assets, (iv) recommend to
the stockholders a dissolution of the corporation or a revocation of a
dissolution, or (v) amend the Bylaws of the corporation; and, unless the board
resolution establishing the committee, the 
<PAGE>
 
Bylaws or the certificate of incorporation expressly so provide, no such
committee shall have the power or authority to declare a dividend, to authorize
the issuance of stock, or to adopt a certificate of ownership and merger
pursuant to Section 253 of the General Corporation Law of Delaware.

         4.2      COMMITTEE MINUTES
                  -----------------

         Each committee shall keep regular minutes of its meetings and report
the same to the Board of Directors when required.

         4.3      MEETINGS AND ACTION OF COMMITTEES
                  ---------------------------------

         Meetings and actions of committees shall be governed by, and held and
taken in accordance with, the provisions of Article III of these Bylaws, Section
3.5 (place of meetings and meetings by telephone), Section 3.6 (regular
meetings), Section 3.7 (special meetings and notice), Section 3.8 (quorum),
Section 3.9 (waiver of notice), and Section 3.10 (action without a meeting),
with such changes in the context of those Bylaws as are necessary to substitute
the committee and its members for the Board of Directors and its members;
provided, however, that the time of regular meetings of committees may be
determined either by resolution of the Board of Directors or by resolution of
the committee, that special meetings of committees may also be called by
resolution of the Board of Directors and that notice of special meetings of
committees shall also be given to all alternate members, who shall have the
right to attend all meetings of the committee. The Board of Directors may adopt
rules for the government of any committee not inconsistent with the provisions
of these Bylaws.

                                    ARTICLE V

                                    OFFICERS
                                    --------

         5.1      OFFICERS
                  --------

         The officers of the corporation shall be a chief executive officer, a
president, a secretary, and a chief financial officer. The corporation may also
have, at the discretion of the Board of Directors, one or more vice presidents,
one or more assistant secretaries, one or more assistant treasurers, and any
such other officers as may be appointed in accordance with the provisions of
Section 5.3 of these Bylaws. Any number of offices may be held by the same
person.

         5.2      APPOINTMENT OF OFFICERS
                  -----------------------

         The officers of the corporation, except such officers as may be
appointed in accordance with the provisions of Sections 5.3 or 5.5 of these
Bylaws, shall be appointed by the Board of Directors, subject to the rights, if
any, of an officer under any contract of employment.
<PAGE>
 
         5.3      SUBORDINATE OFFICERS
                  --------------------
         The Board of Directors may appoint, or empower the chief executive
officer or the president to appoint, such other officers and agents as the
business of the corporation may require, each of whom shall hold office for such
period, have such authority, and perform such duties as are provided in these
Bylaws or as the Board of Directors may from time to time determine.

         5.4      REMOVAL AND RESIGNATION OF OFFICERS
                  -----------------------------------

         Subject to the rights, if any, of an officer under any contract of
employment, any officer may be removed, either with or without cause, by an
affirmative vote of the majority of the Board of Directors at any regular or
special meeting of the board or, except in the case of an officer chosen by the
Board of Directors, by any officer upon whom such power of removal may be
conferred by the Board of Directors.

         Any officer may resign at any time by giving written notice to the
corporation. Any resignation shall take effect at the date of the receipt of
that notice or at any later time specified in that notice; and, unless otherwise
specified in that notice, the acceptance of the resignation shall not be
necessary to make it effective. Any resignation is without prejudice to the
rights, if any, of the corporation under any contract to which the officer is a
party.

         5.5      VACANCIES IN OFFICES
                  --------------------

         Any vacancy occurring in any office of the corporation shall be filled
by the Board of Directors.

         5.6      CHIEF EXECUTIVE OFFICER
                  -----------------------

         Subject to such supervisory powers, if any, as may be given by the
Board of Directors to the chairman of the board, the chief executive officer of
the corporation shall, subject to the control of the Board of Directors, have
general supervision, direction, and control of the business and the officers of
the corporation. The chief executive officer shall preside at all meetings of
the stockholders and, in the absence or nonexistence of a chairman of the board,
at all meetings of the Board of Directors. The chief executive officer shall
have the general powers and duties of management usually vested in the office of
chief executive officer of a corporation and shall have such other powers and
duties as may be prescribed by the Board of Directors or these Bylaws.

         5.7      PRESIDENT
                  ---------

         Subject to such supervisory powers, if any, as may be given by the
Board of Directors to the chairman of the board or the chief executive officer,
the president shall have general supervision, direction, and control of the
business and other officers of the corporation. The President shall have the
general powers and duties of management usually vested in the office of
<PAGE>
 
president of a corporation and shall have such other powers and duties as may be
prescribed by the Board of Directors or these Bylaws.

         5.8      VICE PRESIDENTS
                  ---------------

         In the absence or disability of the chief executive officer and
president, the vice presidents, if any, in order of their rank as fixed by the
Board of Directors or, if not ranked, a vice president designated by the Board
of Directors, shall perform all the duties of the president and when so acting
shall have all the powers of, and be subject to all the restrictions upon, the
president. The vice presidents shall have such other powers and perform such
other duties as from time to time may be prescribed for them respectively by the
Board of Directors, these Bylaws, the president or the chairman of the board.

         5.9      SECRETARY
                  ---------

         The secretary shall keep or cause to be kept, at the principal
executive office of the corporation or such other place as the Board of
Directors may direct, a book of minutes of all meetings and actions of
directors, committees of directors, and stockholders. The minutes shall show the
time and place of each meeting, the names of those present at directors'
meetings or committee meetings, the number of shares present or represented at
stockholders, meetings, and the proceedings thereof.

         The secretary shall keep, or cause to be kept, at the principal
executive office of the corporation or at the office of the corporation's
transfer agent or registrar, as determined by resolution of the Board of
Directors, a share register, or a duplicate share register, showing the names of
all stockholders and their addresses, the number and classes of shares held by
each, the number and date of certificates evidencing such shares, and the number
and date of cancellation of every certificate surrendered for cancellation.

         The secretary shall give, or cause to be given, notice of all meetings
of the stockholders and of the Board of Directors required to be given by law or
by these Bylaws. The secretary shall keep the seal of the corporation, if one be
adopted, in safe custody and shall have such other powers and perform such other
duties as may be prescribed by the Board of Directors or by these Bylaws.

         5.10     CHIEF FINANCIAL OFFICER
                  -----------------------

         The chief financial officer shall keep and maintain, or cause to be
kept and maintained, adequate and correct books and records of accounts of the
properties and business transactions of the corporation, including accounts of
its assets, liabilities, receipts, disbursements, gains, losses, capital
retained earnings, and shares. The books of account shall at all reasonable
times be open to inspection by any director.

         The chief financial officer shall deposit all moneys and other
valuables in the name and to the credit of the corporation with such
depositories as may be designated by the Board of 
<PAGE>
 
Directors. The chief financial officer shall disburse the funds of the
corporation as may be ordered by the Board of Directors, shall render to the
president and directors, whenever they request it, an account of all his or her
transactions as chief financial officer and of the financial condition of the
corporation, and shall have other powers and perform such other duties as may be
prescribed by the Board of Directors or the Bylaws.

         5.11     REPRESENTATION OF SHARES OF OTHER CORPORATIONS
                  ----------------------------------------------

         The chairman of the board, the chief executive officer, the president,
any vice president, the chief financial officer, the secretary or assistant
secretary of this corporation, or any other person authorized by the Board of
Directors or the chief executive officer or the president or a vice president,
is authorized to vote, represent, and exercise on behalf of this corporation all
rights incident to any and all shares of any other corporation or corporations
standing in the name of this corporation. The authority granted herein may be
exercised either by such person directly or by any other person authorized to do
so by proxy or power of attorney duly executed by such person having the
authority.

         5.12     AUTHORITY AND DUTIES OF OFFICERS
                  --------------------------------

         In addition to the foregoing authority and duties, all officers of the
corporation shall respectively have such authority and perform such duties in
the management of the business of the corporation as may be designated from time
to time by the Board of Directors or the stockholders.

                                   ARTICLE VI

                     INDEMNIFICATION OF DIRECTORS, OFFICERS,
                     --------------------------------------
                            EMPLOYEES AND OTHER AGENTS
                            --------------------------

         6.1      INDEMNIFICATION OF DIRECTORS AND OFFICERS
                  -----------------------------------------

         The corporation shall, to the maximum extent and in the manner
permitted by the General Corporation Law of Delaware, indemnify each of its
directors and officers against expenses (including attorneys' fees), judgments,
fines, settlements and other amounts actually and reasonably incurred in
connection with any proceeding, arising by reason of the fact that such person
is or was an agent of the corporation. For purposes of this Section 6.1, a
"director" or "officer" of the corporation includes any person (i) who is or was
a director or officer of the corporation, (ii) who is or was serving at the
request of the corporation as a director or officer of another corporation,
partnership, joint venture, trust or other enterprise, or (iii) who was a
director or officer of a corporation which was a predecessor corporation of the
corporation or of another enterprise at the request of such predecessor
corporation.
<PAGE>
 
         6.2      INDEMNIFICATION OF OTHERS
                  -------------------------

         The corporation shall have the power, to the maximum extent and in the
manner permitted by the General Corporation Law of Delaware, to indemnify each
of its employees and agents (other than directors and officers) against expenses
(including attorneys' fees), judgments, fines, settlements and other amounts
actually and reasonably incurred in connection with any proceeding, arising by
reason of the fact that such person is or was an agent of the corporation. For
purposes of this Section 6.2, an "employee" or "agent" of the corporation (other
than a director or officer) includes any person (i) who is or was an employee or
agent of the corporation, (ii) who is or was serving at the request of the
corporation as an employee or agent of another corporation, partnership, joint
venture, trust or other enterprise, or (iii) who was an employee or agent of a
corporation which was a predecessor corporation of the corporation or of another
enterprise at the request of such predecessor corporation.

         6.3      PAYMENT OF EXPENSES IN ADVANCE.
                  ------------------------------

         Expenses incurred in defending any action or proceeding for which
indemnification is required pursuant to Section 6.1 or for which indemnification
is permitted pursuant to Section 6.2 following authorization thereof by the
Board of Directors shall be paid by the corporation in advance of the final
disposition of such action or proceeding upon receipt of an undertaking by or on
behalf of the indemnified party to repay such amount if it shall ultimately be
determined that the indemnified party is not entitled to be indemnified as
authorized in this Article VI.

         6.4      INDEMNITY NOT EXCLUSIVE.
                  -----------------------

         The indemnification provided by this Article VI shall not be deemed
exclusive of any other rights to which those seeking indemnification may be
entitled under any bylaw, agreement, vote of shareholders or disinterested
directors or otherwise, both as to action in an official capacity and as to
action in another capacity while holding such office, to the extent that such
additional rights to indemnification are authorized in the certificate of
incorporation.

         6.5      INSURANCE
                  ---------

         The corporation may purchase and maintain insurance on behalf of any
person who is or was a director, officer, employee or agent of the corporation,
or is or was serving at the request of the corporation as a director, officer,
employee or agent of another corporation, partnership, joint venture, trust or
other enterprise against any liability asserted against him or her and incurred
by him or her in any such capacity, or arising out of his or her status as such,
whether or not the corporation would have the power to indemnify him or her
against such liability under the provisions of the General Corporation Law of
Delaware.
<PAGE>
 
         6.6      CONFLICTS.
                  ---------

                  No indemnification or advance shall be made under this Article
VI, except where such indemnification or advance is mandated by law or the
order, judgment or decree of any court of competent jurisdiction, in any
circumstance where it appears:

                  (a) That it would be inconsistent with a provision of the
certificate of incorporation, these Bylaws, a resolution of the stockholders or
an agreement in effect at the time of the accrual of the alleged cause of the
action asserted in the proceeding in which the expenses were incurred or other
amounts were paid, which prohibits or otherwise limits indemnification; or

                  (b) That it would be inconsistent with any condition expressly
imposed by a court in approving a settlement.


                                   ARTICLE VII

                               RECORDS AND REPORTS
                               -------------------

         7.1      MAINTENANCE AND INSPECTION OF RECORDS
                  -------------------------------------

         The corporation shall, either at its principal executive offices or at
such place or places as designated by the Board of Directors, keep a record of
its stockholders listing their names and addresses and the number and class of
shares held by each stockholder, a copy of these Bylaws as amended to date,
accounting books, and other records.

         Any stockholder of record, in person or by attorney or other agent,
shall, upon written demand under oath stating the purpose thereof, have the
right during the usual hours for business to inspect for any proper purpose the
corporation's stock ledger, a list of its stockholders, and its other books and
records and to make copies or extracts therefrom. A proper purpose shall mean a
purpose reasonably related to such person's interest as a stockholder. In every
instance where an attorney or other agent is the person who seeks the right to
inspection, the demand under oath shall be accompanied by a power of attorney or
such other writing that authorizes the attorney or other agent to so act on
behalf of the stockholder. The demand under oath shall be directed to the
corporation at its registered office in Delaware or at its principal place of
business.

         7.2      INSPECTION BY DIRECTORS
                  -----------------------

         Any director shall have the right to examine the corporation's stock
ledger, a list of its stockholders, and its other books and records for a
purpose reasonably related to his position as a director. The Court of Chancery
is hereby vested with the exclusive jurisdiction to determine whether a director
is entitled to the inspection sought. The Court may summarily order the
corporation to permit the director to inspect any and all books and records, the
stock ledger, and the stock list and to make copies or extracts therefrom. The
Court may, in its discretion, 
<PAGE>
 
prescribe any limitations or conditions with reference to the inspection, or
award such other and further relief as the Court may deem just and proper.


         7.3      ANNUAL STATEMENT TO STOCKHOLDERS
                  --------------------------------

         The Board of Directors shall present at each annual meeting, and at any
special meeting of the stockholders when called for by vote of the stockholders,
a full and clear statement of the business and condition of the corporation.

                                  ARTICLE VIII

                                 GENERAL MATTERS
                                 ---------------

         8.1      CHECKS
                  ------

         From time to time, the Board of Directors shall determine by resolution
which person or persons may sign or endorse all checks, drafts, other orders for
payment of money, notes or other evidences of indebtedness that are issued in
the name of or payable to the corporation, and only the persons so authorized
shall sign or endorse those instruments.

         8.2      EXECUTION OF CORPORATE CONTRACTS AND INSTRUMENTS
                  ------------------------------------------------

         The Board of Directors, except as otherwise provided in these Bylaws,
may authorize any officer or officers, or agent or agents, to enter into any
contract or execute any instrument in the name of and on behalf of the
corporation; such authority may be general or confined to specific instances.
Unless so authorized or ratified by the Board of Directors or within the agency
power of an officer, no officer, agent or employee shall have any power or
authority to bind the corporation by any contract or engagement or to pledge its
credit or to render it liable for any purpose or for any amount.

         8.3      STOCK CERTIFICATES; PARTLY PAID SHARES
                  --------------------------------------

         The shares of a corporation shall be represented by certificates,
provided that the Board of Directors of the corporation may provide by
resolution or resolutions that some or all of any or all classes or series of
its stock shall be uncertificated shares. Any such resolution shall not apply to
shares represented by a certificate until such certificate is surrendered to the
corporation. Notwithstanding the adoption of such a resolution by the Board of
Directors, every holder of stock represented by certificates and upon request
every holder of uncertificated shares shall be entitled to have a certificate
signed by, or in the name of the corporation by the chairman or vice-chairman of
the Board of Directors, or the chief executive officer or the president or vice
president, and by the chief financial officer or an assistant treasurer, or the
secretary or an assistant secretary of such corporation representing the number
of shares registered in certificate form. Any or all of the signatures on the
certificate may be a facsimile. In case any officer, transfer agent or registrar
who has signed or whose facsimile signature has been placed upon a certificate
has ceased to be such officer, transfer agent or registrar before such
certificate is 
<PAGE>
 
issued, it may be issued by the corporation with the same effect as if he or she
were such officer, transfer agent or registrar at the date of issue.


         The corporation may issue the whole or any part of its shares as partly
paid and subject to call for the remainder of the consideration to be paid
therefor. Upon the face or back of each stock certificate issued to represent
any such partly paid shares, upon the books and records of the corporation in
the case of uncertificated partly paid shares, the total amount of the
consideration to be paid therefor and the amount paid thereon shall be stated.
Upon the declaration of any dividend on fully paid shares, the corporation shall
declare a dividend upon partly paid shares of the same class, but only upon the
basis of the percentage of the consideration actually paid thereon.

         8.4      SPECIAL DESIGNATION ON CERTIFICATES
                  -----------------------------------

         If the corporation is authorized to issue more than one class of stock
or more than one series of any class, then the powers, the designations, the
preferences, and the relative, participating, optional or other special rights
of each class of stock or series thereof and the qualifications, limitations or
restrictions of such preferences and/or rights shall be set forth in full or
summarized on the face or back of the certificate that the corporation shall
issue to represent such class or series of stock; provided, however, that,
                                                  -----------------
except as otherwise provided in Section 202 of the General Corporation Law of
Delaware, in lieu of the foregoing requirements there may be set forth on the
face or back of the certificate that the corporation shall issue to represent
such class or series of stock a statement that the corporation will furnish
without charge to each stockholder who so requests the powers, the designations,
the preferences, and the relative, participating, optional or other special
rights of each class of stock or series thereof and the qualifications,
limitations or restrictions of such preferences and/or rights.

         8.5      LOST CERTIFICATES
                  -----------------

         Except as provided in this Section 8.5, no new certificates for shares
shall be issued to replace a previously issued certificate unless the latter is
surrendered to the corporation and canceled at the same time. The corporation
may issue a new certificate of stock or uncertificated shares in the place of
any certificate theretofore issued by it, alleged to have been lost, stolen or
destroyed, and the corporation may require the owner of the lost, stolen or
destroyed certificate, or his legal representative, to give the corporation a
bond sufficient to indemnify it against any claim that may be made against it on
account of the alleged loss, theft or destruction of any such certificate or the
issuance of such new certificate or uncertificated shares.

         8.6      CONSTRUCTION; DEFINITIONS
                  -------------------------

         Unless the context requires otherwise, the general provisions, rules of
construction, and definitions in the Delaware General Corporation Law shall
govern the construction of these Bylaws. Without limiting the generality of this
provision, the singular number includes the plural, the plural number includes
the singular, and the term "person" includes both a corporation and a natural
person.
<PAGE>
 
         8.7      DIVIDENDS
                  ---------
         The directors of the corporation, subject to any restrictions contained
in (i) the General Corporation Law of Delaware or (ii) the certificate of
incorporation, may declare and pay dividends upon the shares of its capital
stock. Dividends may be paid in cash, in property, or in shares of the
corporation's capital stock.

         The directors of the corporation may set apart out of any of the funds
of the corporation available for dividends a reserve or reserves for any proper
purpose and may abolish any such reserve. Such purposes shall include but not be
limited to equalizing dividends, repairing or maintaining any property of the
corporation, and meeting contingencies.

         8.8      FISCAL YEAR
                  -----------

         The fiscal year of the corporation shall be fixed by resolution of the
Board of Directors and may be changed by the Board of Directors.

         8.9      SEAL
                  ----

         The corporation may adopt a corporate seal, which may be altered at
pleasure, and may use the same by causing it or a facsimile thereof, to be
impressed or affixed or in any other manner reproduced.

         8.10     TRANSFER OF STOCK
                  -----------------

         Upon surrender to the corporation or the transfer agent of the
corporation of a certificate for shares duly endorsed or accompanied by proper
evidence of succession, assignation or authority to transfer, it shall be the
duty of the corporation to issue a new certificate to the person entitled
thereto, cancel the old certificate, and record the transaction in its books.

         8.11     STOCK TRANSFER AGREEMENTS
                  -------------------------

         The corporation shall have power to enter into and perform any
agreement with any number of stockholders of any one or more classes of stock of
the corporation to restrict the transfer of shares of stock of the corporation
of any one or more classes owned by such stockholders in any manner not
prohibited by the General Corporation Law of Delaware.

         8.12     REGISTERED STOCKHOLDERS
                  -----------------------

         The corporation shall be entitled to recognize the exclusive right of a
person registered on its books as the owner of shares to receive dividends and
to vote as such owner, shall be entitled to hold liable for calls and
assessments the person registered on its books as the owner of shares, and shall
not be bound to recognize any equitable or other claim to or interest in such
share or 
<PAGE>
 
shares on the part of another person, whether or not it shall have express or
other notice thereof, except as otherwise provided by the laws of Delaware.


                                   ARTICLE IX

                                   AMENDMENTS
                                   ----------

         The Bylaws of the corporation may be adopted, amended or repealed by
the stockholders entitled to vote; provided, however, that the corporation may,
in its certificate of incorporation, confer the power to adopt, amend or repeal
Bylaws upon the directors. The fact that such power has been so conferred upon
the directors shall not divest the stockholders of the power, nor limit their
power to adopt, amend or repeal Bylaws.

<PAGE>
 
                                                                     EXHIBIT 4.1
================================================================================



                                KERAVISION, INC.

                                       AND

                                BANKBOSTON, N.A.

                                  RIGHTS AGENT






                        PREFERRED SHARES RIGHTS AGREEMENT







                           Dated as of August 18, 1997


================================================================================
<PAGE>
 
<TABLE> 
<CAPTION> 
                                TABLE OF CONTENTS


                                                                                                       Page
<S>                                                                                                    <C> 
Section 1. Certain Definitions...........................................................................1
           -------------------
Section 2. Appointment of Rights Agent...................................................................5
           ---------------------------
Section 3. Issuance of Rights Certificate................................................................5
           ------------------------------
Section 4. Form of Rights Certificate....................................................................7
           --------------------------
Section 5. Countersignature and Registration.............................................................8
           ---------------------------------
Section 6. Transfer, Split Up, Combination and Exchange of Rights Certificates;
           -------------------------------------------------------------------
           Mutilated, Destroyed, Lost or Stolen Rights Certificates......................................8
           --------------------------------------------------------
Section 7. Exercise of Rights; Purchase Price; Expiration Date of Right..................................9
           ------------------------------------------------------------
Section 8. Cancellation and Destruction of Rights Certificate...........................................11
           --------------------------------------------------
Section 9. Reservation and Availability of Preferred Share..............................................11
           -----------------------------------------------
Section 10. Preferred Shares Record Date................................................................12
            ----------------------------
Section 11. Adjustment of Purchase Price, Number of Shares or Number of Right...........................13
            -----------------------------------------------------------------
Section 12. Certificate of Adjusted Purchase Price or Number of Shares..................................20
            ----------------------------------------------------------
Section 13. Consolidation, Merger or Sale or Transfer of Assets or Earning Power........................20
            --------------------------------------------------------------------
Section 14. Fractional Rights and Fractional Shares.....................................................23
            ---------------------------------------
Section 15. Rights of Action............................................................................24
            ----------------
Section 16. Agreement of Rights Holders.................................................................24
            ---------------------------
Section 17. Rights Certificate Holder Not Deemed a Stockholder..........................................25
            --------------------------------------------------
Section 18. Concerning the Rights Agent.................................................................25
            ---------------------------
Section 19. Merger or Consolidation or Change of Name of Rights Agent...................................25
            ---------------------------------------------------------
Section 20. Duties of Rights Agent......................................................................26
            ----------------------
Section 21. Change of Rights Agent......................................................................28
            ----------------------
Section 22. Issuance of New Rights Certificates.........................................................29
            -----------------------------------
Section 23. Redemption..................................................................................29
            ----------
Section 24. Exchange....................................................................................30
            --------
Section 25. Notice of Certain Events....................................................................32
            ------------------------
Section 26. Notices.....................................................................................32
            -------
Section 27. Supplements and Amendments..................................................................33
            --------------------------
Section 28. Successors..................................................................................33
            ----------
Section 29. Determinations and Actions by the Board of Directors, etc...................................33
            ---------------------------------------------------------
Section 30. Benefits of this Agreement..................................................................34
            --------------------------
Section 31. Severability................................................................................34
            ------------
Section 32. Governing Law...............................................................................34
            -------------
Section 33. Counterparts................................................................................34
            ------------
Section 34. Descriptive Headings........................................................................35
            --------------------
</TABLE> 
<PAGE>
 
                               TABLE OF CONTENTS
                                  (CONTINUED)

                                                                        Page
                                                                        ----

EXHIBITS

Exhibit A         Form of Certificate of Designation

Exhibit B         Form of Rights Certificate

Exhibit C         Summary of Rights









                                     -iii-
<PAGE>
 
                        PREFERRED SHARES RIGHTS AGREEMENT
                        ---------------------------------

         Agreement, dated as of August 18, 1997, between KeraVision, Inc., a
Delaware corporation (the "COMPANY"), and BankBoston, N.A. (the "RIGHTS AGENT").

         On August 18, 1997 (the "RIGHTS DIVIDEND DECLARATION DATE"), the Board
of Directors of the Company authorized and declared a dividend of one Preferred
Share purchase right (a "RIGHT") for each Common Share (as hereinafter defined)
of the Company outstanding as of the Close of Business (as hereinafter defined)
on September 8, 1997 (the "RECORD DATE"), each Right representing the right to
purchase one one-thousandth of a share of Series A Participating Preferred Stock
(as such number may be adjusted pursuant to the provisions of this Agreement),
having the rights, preferences and privileges set forth in the form of
Certificate of Designation of Rights, Preferences and Privileges of Series A
Participating Preferred Stock attached hereto as Exhibit A, upon the terms and
subject to the conditions herein set forth, and further authorized and directed
the issuance of one Right (as such number may be adjusted pursuant to the
provisions of this Agreement) with respect to each Common Share that shall
become outstanding between the Record Date and the earlier of the Distribution
Date and the Expiration Date (as such terms are hereinafter defined), and in
certain circumstances after the Distribution Date.

         NOW, THEREFORE, in consideration of the promises and the mutual
agreements herein set forth, the parties hereby agree as follows:

         Section 1.   Certain  Definitions.  For  purposes of this  
                      --------------------
Agreement the following terms have the meanings indicated:

                  (a) "ACQUIRING PERSON" shall mean any Person who or which,
together with all Affiliates and Associates of such Person, shall be the
Beneficial Owner of 20% or more of the Common Shares then outstanding, but shall
not include the Company, any Subsidiary of the Company or any employee benefit
plan of the Company or of any Subsidiary of the Company, or any entity holding
Common Shares for or pursuant to the terms of any such plan. Notwithstanding the
foregoing, no Person shall be deemed to be an Acquiring Person either (i) as the
result of an acquisition of Common Shares by the Company which, by reducing the
number of shares outstanding, increases the proportionate number of shares
beneficially owned by such Person to 20% or more of the Common Shares of the
Company then outstanding; provided, however, that if a Person shall become the
Beneficial Owner of 20% or more of the Common Shares of the Company then
outstanding by reason of share purchases by the Company and shall, after such
share purchases by the Company, become the Beneficial Owner of any additional
Common Shares of the Company, then such Person shall be deemed to be an
Acquiring Person, or (ii) if within eight days after such Person would otherwise
become an Acquiring Person (but for the operation of this clause (ii)), such
Person notifies the Board of Directors that such Person did so inadvertently and
within two days after such notification, such Person is the Beneficial Owner of
less than 20% of the outstanding Common Shares.
<PAGE>
 
                  (b) "AFFILIATE" and "ASSOCIATE" shall have the respective
meanings ascribed to such terms in Rule 12b-2 of the General Rules and
Regulations under the Securities and Exchange Act of 1934, as amended (the
"EXCHANGE ACT"), as in effect on the date of this Agreement.

                  (c) A Person shall be deemed the "BENEFICIAL OWNER" of
and shall be deemed to "BENEFICIALLY OWN" any securities:

                           (i)      which such Person or any of such Person's
Affiliates or Associates beneficially owns, directly or indirectly, for purposes
of Section 13(d) of the Exchange Act and Rule 13d-3 thereunder (or any
comparable or successor law or regulation);

                           (ii)     which such Person or any of such Person's
Affiliates or Associates has (A) the right to acquire (whether such right is
exercisable immediately or only after the passage of time) pursuant to any
agreement, arrangement or understanding (other than customary agreements with
and between underwriters and selling group members with respect to a bona fide
public offering of securities), or upon the exercise of conversion rights,
exchange rights, rights (other than the Rights), warrants or options, or
otherwise; provided, however, that a Person shall not be deemed pursuant to this
           --------  -------
Section l(c)(ii)(A) the Beneficial Owner of, or to beneficially own, (1)
securities tendered pursuant to a tender or exchange offer made by or on behalf
of such Person or any of such Person's Affiliates or Associates until such
tendered securities are accepted for purchase or exchange, or (2) securities
which a Person or any of such Person's Affiliates or Associates may be deemed to
have the right to acquire pursuant to any merger or other acquisition agreement
between the Company and such Person (or one or more of its Affiliates or
Associates) if such agreement has been approved by the Board of Directors of the
Company prior to there being an Acquiring Person; or (B) the right to vote
pursuant to any agreement, arrangement or understanding; provided, however, that
                                                         --------  -------
a Person shall not be deemed the Beneficial Owner of, or to beneficially own,
any security under this Section l(c)(ii)(B) if the agreement, arrangement or
understanding to vote such security (1) arises solely from a revocable proxy or
consent given to such Person in response to a public proxy or consent
solicitation made pursuant to, and in accordance with, the applicable rules and
regulations of the Exchange Act and (2) is not also then reportable on Schedule
13D under the Exchange Act (or any comparable or successor report); or


                           (iii)    which are beneficially owned, directly or
indirectly, by any other Person (or any Affiliate or Associate thereof) with
which such Person or any of such Person's Affiliates or Associates has any
agreement, arrangement or understanding (whether or not in writing) (other than
customary agreements with and between underwriters and selling group members
with respect to a bona fide public offering of securities) for the purpose of
acquiring, holding, voting (except to the extent contemplated by the proviso to
Section l(c)(ii)(B)) or disposing of any securities of the Company; provided,
                                                                    --------
however, that in no case shall an officer or director of the Company be deemed
- -------
(x) the Beneficial Owner of any securities beneficially owned by another officer
or director of the Company solely by reason of actions undertaken by such
persons in their capacity as officers or directors of the Company or (y) the
Beneficial Owner of securities held of record by the trustee of any employee
benefit plan of the Company or any 

                                      -2-
<PAGE>
 
Subsidiary of the Company for the benefit of any employee of the Company or any
Subsidiary of the Company, other than the officer or director, by reason of any
influence that such officer or director may have over the voting of the
securities held in the plan.

                  (d) "BUSINESS DAY" shall mean any day other than a Saturday,
Sunday or a day on which banking institutions in Boston, Massachusetts are
authorized or obligated by law or executive order to close.

                  (e) "CLOSE OF BUSINESS" on any given date shall mean 5:00
P.M., Boston, Maasachusetts time (EST), on such date; provided, however, that if
such date is not a Business Day it shall mean 5:00 P.M., Boston, Massachusetts
time (EST), on the next succeeding Business Day.

                  (f) "COMMON SHARES" when used with reference to the Company
shall mean the shares of Common Stock of the Company, $0.001 par value. "Common
Shares" when used with reference to any Person other than the Company shall mean
the capital stock (or equity interest) with the greatest voting power of such
other Person or, if such other Person is a Subsidiary of another Person, the
Person or Persons which ultimately control such first-mentioned Person.

                  (g) "CONTINUING DIRECTOR" shall mean (i) any member of the
Board of Directors of the Company, while a member of the Board, who is not an
Acquiring Person, or an Affiliate or Associate of an Acquiring Person, or a
representative of an Acquiring Person or of any such Affiliate or Associate, and
who was a member of the Board prior to the date of this Agreement, or (ii) any
Person who subsequently becomes a member of the Board, while a member of the
Board, who is not an Acquiring Person, or an Affiliate or Associate of an
Acquiring Person, or a representative of an Acquiring Person or of any such
Affiliate or Associate, if such Person's nomination for election or election to
the Board is recommended or approved by a majority of the Continuing Directors.

                  (h) "DISTRIBUTION DATE" shall mean the earlier of (i) the
Close of Business on the tenth day (or such later date as may be determined by
action of a majority of Continuing Directors then in office) after the Shares
Acquisition Date (or, if the tenth day after the Shares Acquisition Date occurs
before the Record Date, the Close of Business on the Record Date) or (ii) the
Close of Business on the tenth day (or such later date as may be determined by
action of a majority of Continuing Directors then in office) after the date that
a tender or exchange offer by any Person (other than the Company, any Subsidiary
of the Company, any employee benefit plan of the Company or of any Subsidiary of
the Company, or any Person or entity organized, appointed or established by the
Company for or pursuant to the terms of any such plan) is first published or
sent or given within the meaning of Rule 14d-2(a) of the General Rules and
Regulations under the Exchange Act, if, assuming the successful consummation
thereof, such Person would be the Beneficial Owner of 20% or more of the shares
of Common Stock then outstanding.

                                      -3-
<PAGE>
 
                  (i) "EQUIVALENT SHARES" shall mean Preferred Shares and any
other class or series of capital stock of the Company that is entitled to
participate in dividends and other distributions, including distributions upon
the liquidation, dissolution or winding up of the Company, on a proportional
basis with the Common Shares. In calculating the number of any class or series
of Equivalent Shares for purposes of Section 11 of this Rights Agreement, the
number of shares, or fractions of a share, of such class or series of capital
stock that is entitled to the same dividend or distribution as a whole Common
Share shall be deemed to be one share.

                  (j) "EXPIRATION DATE" shall mean the earliest of (i) the Close
of Business on the Final Expiration Date, (ii) the Redemption Date, (iii) the
time at which the Board of Directors orders the exchange of the Rights as
provided in Section 24 hereof or (iv) the consummation of a transaction
contemplated by Section 13(d) hereof.

                  (k) "FINAL EXPIRATION DATE" shall mean August 17, 2007.

                  (1) "PERMITTED OFFER" shall mean a tender offer for all
outstanding Common Shares made in the manner prescribed by Section 14(d) of the
Exchange Act and the rules and regulations promulgated thereunder; provided,
                                                                   --------
however, that such tender offer occurs at a time when Continuing Directors are
- -------
in office and a majority of the Continuing Directors then in office has
determined that the offer is both adequate and otherwise in the best interests
of the Company and its stockholders (taking into account all factors that such
Continuing Directors deem relevant, including without limitation prices that
could reasonably be achieved if the Company or its assets were sold on an
orderly basis designed to realize maximum value).

                  (m) "PERSON" shall mean any individual, firm, corporation or
other entity, and shall include any successor (by merger or otherwise) of such
entity.

                  (n) "PREFERRED SHARES" shall mean shares of Series A
Participating Preferred Stock of the Company.

                  (o) "PURCHASE PRICE" shall have the meaning set forth in
Section 4(a) hereof.

                  (p) "RECORD DATE" shall have the meaning set forth in the
recitals at the beginning of this Agreement.

                  (q) "REDEMPTION DATE" shall mean the time at which the Board
of Directors of the Company orders redemption of the Rights as provided in
Section 23 hereof.

                  (r) "REDEMPTION PRICE" shall have the meaning set forth in
Section 23(a) hereof.

                  (s) "RIGHTS DIVIDEND DECLARATION DATE" shall have the meaning
set forth in the recitals at the beginning of this Agreement.


                                      -4-
<PAGE>
 
                  (t) "SECTION 13 EVENT" shall mean any event described in
clause (i), (ii) or (iii) of Section 13(a) hereof.

                  (u) "SHARES ACQUISITION DATE" shall mean the first date of
public announcement (which, for purposes of this definition, shall include,
without limitation, a report filed pursuant to Section 13(d) under the Exchange
Act) by the Company or an Acquiring Person that an Acquiring Person has become
such; provided that, if such Person is determined not to have become an
      -------- ----
Acquiring Person pursuant to Section l(a)(ii) hereof, then no Shares Acquisition
Date shall be deemed to have occurred.

                  (v) "SUBSIDIARY" of any Person shall mean any corporation or
other entity of which an amount of voting securities sufficient to elect a
majority of the directors or Persons having similar authority of such
corporation or other entity is beneficially owned, directly or indirectly, by
such Person, or any corporation or other entity otherwise controlled by such
Person.

                  (w) "TOTAL EXERCISE PRICE" shall have the meaning set forth in
Section 4(a) hereof.

                  (x) "TRADING DAY" shall have the meaning set forth in Section
11(d) hereof.

                  (y) A "TRIGGERING EVENT" shall be deemed to have occurred upon
any Person (other than the Company, any Subsidiary of the Company, any employee
benefit plan of the Company or any Subsidiary of the Company, or any entity
holding Common Shares for or pursuant to the terms of any such plan), together
with all Affiliates and Associates of such Person, becoming an Acquiring Person.

         Section 2. Appointment of Rights Agent. The Company hereby appoints the
                    ---------------------------
Rights Agent to act as agent for the Company in accordance with the terms and
conditions hereof, and the Rights Agent hereby accepts such appointment. The
Company may from time to time appoint such co-Rights Agents as it may deem
necessary or desirable.

         Section 3. Issuance of Rights Certificates.
                    -------------------------------

                 (a) Until the Distribution Date, (i) the Rights will be
evidenced (subject to the provisions of Sections 3(b) and 3(c) hereof) by the
certificates for Common Shares registered in the names of the holders thereof
(which certificates shall also be deemed to be Rights Certificates) and not by
separate Rights Certificates and (ii) the right to receive Rights Certificates
will be transferable only in connection with the transfer of Common Shares.
Until the earlier of the Distribution Date or the Expiration Date, the surrender
for transfer of such certificates for Common Shares shall also constitute the
surrender for transfer of the Rights associated with the Common Shares
represented thereby. As soon as practicable after the Distribution Date, the
Company will prepare and execute, the Rights Agent will countersign, and the
Company will send or cause to be sent (and the Rights Agent will, if requested,
send) by first-class, postage-prepaid mail, to each record holder of Common
Shares as of the close of business on the Distribution Date, at the address of
such holder shown on the records of the 

                                      -5-
<PAGE>
 
Company, a Rights Certificate, in substantially the form of Exhibit B hereto (a
                                                            ---------
"RIGHTS CERTIFICATE"), evidencing one Right for each Common Share so held,
subject to adjustment as provided herein. In the event that an adjustment in the
number of Rights per Common Share has been made pursuant to Section 11(a)(i),
Section 11(i) or Section 11(p) hereof, then at the time of distribution of the
Rights Certificates, the Company shall make the necessary and appropriate
rounding adjustments (in accordance with Section 14(a) hereof) so that Rights
Certificates representing only whole numbers of Rights are distributed and cash
is paid in lieu of any fractional Rights. As of the Distribution Date, the
Rights will be evidenced solely by such Rights Certificates and may be
transferred by the transfer of the Rights Certificates as permitted hereby,
separately and apart from any transfer of one or more Common Shares, and the
holders of such Rights Certificates as listed in the records of the Company or
any transfer agent or registrar for the Rights shall be the record holders
thereof.

                  (b) On the Record Date or as soon as practicable thereafter,
the Company will send a copy of a Summary of Rights in substantially the form of
Exhibit C hereto (the "SUMMARY OF RIGHTS"), by first-class, postage-prepaid
- ---------
mail, to each record holder of Common Shares as of the close of business on the
Record Date, at the address of such holder shown on the records of the Company.

                  (c) Unless the Board of Directors by resolution adopted at or
before the time of the issuance (including pursuant to the exercise of rights
under the Company's benefit plans) of any Common Shares specifies to the
contrary, Rights shall be issued in respect of all Common Shares that are issued
after the Record Date but prior to the earlier of the Distribution Date or the
Expiration Date or, in certain circumstances provided in Section 22 hereof,
after the Distribution Date. Certificates representing such Common Shares shall
also be deemed to be certificates for Rights, and shall bear the following
legend:

         This certificate also evidences and entitles the holder hereof to
         certain rights as set forth in a Preferred Shares Rights Agreement
         between KeraVision, Inc. and BankBoston, N.A. as the Rights Agent,
         dated as of August 18, 1997 (the "RIGHTS AGREEMENT"), the terms of
         which are hereby incorporated herein by reference and a copy of which
         is on file at the principal executive offices of KeraVision, Inc. Under
         certain circumstances, as set forth in the Rights Agreement, such
         Rights will be evidenced by separate certificates and will no longer be
         evidenced by this certificate. KeraVision, Inc. will mail to the holder
         of this certificate a copy of the Rights Agreement without charge after
         receipt of a written request therefor. Under certain circumstances set
         forth in the Rights Agreement, Rights issued to, or held by, any Person
         who is, was or becomes an Acquiring Person or any Affiliate or
         Associate thereof (as such terms are defined in the Rights Agreement),
         whether currently held by or on behalf of such Person or by any
         subsequent holder, may become null and void.

With respect to such certificates containing the foregoing legend, until the
earlier of (i) the Distribution Date or (ii) the Expiration Date, the Rights
associated with the Common Shares represented by such certificates shall be
evidenced by such certificates alone, and the surrender for transfer of any such
certificate shall also constitute the transfer of the Rights associated with 

                                      -6-
<PAGE>
 
the Common Shares represented thereby. In the event that the Company purchases
or acquires any Common Shares after the Record Date but prior to the
Distribution Date, any Rights associated with such Common Shares shall be deemed
canceled and retired so that the Company shall not be entitled to exercise any
Rights associated with the Common Shares which are no longer outstanding.

         Section 4. Form of Rights Certificates.
                    ---------------------------

                 (a) The Rights Certificates (and the forms of election to
purchase Common Shares and of assignment to be printed on the reverse thereof)
shall be substantially in the form of Exhibit B hereto and may have such marks
of identification or designation and such legends, summaries or endorsements
printed thereon as the Company may deem appropriate and as are not inconsistent
with the provisions of this Agreement, or as may be required to comply with any
applicable law or with any rule or regulation made pursuant thereto or with any
rule or regulation of any stock exchange on which the Rights may from time to
time be listed, or to conform to usage. Subject to the provisions of Section 11
and Section 22 hereof, the Rights Certificates, whenever distributed, shall be
dated as of the Record Date (or in the case of Rights issued with respect to
Common Shares issued by the Company after the Record Date, as of the date of
issuance of such Common Shares) and on their face shall entitle the holders
thereof to purchase such number of one-thousandths of a Preferred Share as shall
be set forth therein at the price set forth therein (such exercise price per one
one-thousandth of a Preferred Share being hereinafter referred to as the
"PURCHASE PRICE" and the aggregate exercise price of all Preferred Shares
issuable upon exercise of one Right being hereinafter referred to as the "TOTAL
EXERCISE PRICE"), but the number and type of securities purchasable upon the
exercise of each Right and the Purchase Price shall be subject to adjustment as
provided herein.

                 (b) Any Rights Certificate issued pursuant to Section 3(a) or
Section 22 hereof that represents Rights beneficially owned by: (i) an Acquiring
Person or any Associate or Affiliate of an Acquiring Person, (ii) a transferee
of an Acquiring Person (or of any such Associate or Affiliate) who becomes a
transferee after the Acquiring Person becomes such or (iii) a transferee of an
Acquiring Person (or of any such Associate or Affiliate) who becomes a
transferee prior to or concurrently with the Acquiring Person becoming such and
receives such Rights pursuant to either (A) a transfer (whether or not for
consideration) from the Acquiring Person to holders of equity interests in such
Acquiring Person or to any Person with whom such Acquiring Person has any
continuing agreement, arrangement or understanding regarding the transferred
Rights or (B) a transfer that the Board of Directors of the Company has
determined is part of a plan, arrangement or understanding that has as a primary
purpose or effect avoidance of Section 7(e) hereof, and any Rights Certificate
issued pursuant to Section 6 or Section 11 hereof upon transfer, exchange,
replacement or adjustment of any other Rights Certificate referred to in this
sentence, shall contain (to the extent feasible) the following legend:

         The Rights represented by this Rights Certificate are or were
         beneficially owned by a Person who was or became an Acquiring Person or
         an Affiliate or Associate of an Acquiring Person (as such terms are
         defined in the Rights Agreement). Accordingly, this 

                                      -7-
<PAGE>
 
         Rights Certificate and the Rights represented hereby may become null
         and void in the circumstances specified in Section 7(e) of the Rights
         Agreement.

         Section 5. Countersignature and Registration.
                    ---------------------------------

                 (a) The Rights Certificates shall be executed on behalf of the
Company by its Chairman of the Board, its Chief Executive Officer, its President
or any Vice President, either manually or by facsimile signature, and by the
Secretary or an Assistant Secretary of the Company, either manually or by
facsimile signature, and shall have affixed thereto the Company's seal (if any)
or a facsimile thereof. The Rights Certificates shall be manually countersigned
by the Rights Agent and shall not be valid for any purpose unless countersigned.
In case any officer of the Company who shall have signed any of the Rights
Certificates shall cease to be such officer of the Company before
countersignature by the Rights Agent and issuance and delivery by the Company,
such Rights Certificates, nevertheless, may be countersigned by the Rights Agent
and issued and delivered by the Company with the same force and effect as though
the person who signed such Rights Certificates had not ceased to be such officer
of the Company; and any Rights Certificate may be signed on behalf of the
Company by any person who, at the actual date of the execution of such Rights
Certificate, shall be a proper officer of the Company to sign such Rights
Certificate, although at the date of the execution of this Rights Agreement any
such person was not such an officer.

                 (b) Following the Distribution Date, the Rights Agent will
keep or cause to be kept, at its office designated for such purposes, books for
registration and transfer of the Rights Certificates issued hereunder. Such
books shall show the names and addresses of the respective holders of the Rights
Certificates, the number of Rights evidenced on its face by each of the Rights
Certificates and the date of each of the Rights Certificates.

         Section 6.   Transfer, Split Up, Combination and Exchange of Rights
                      ------------------------------------------------------
Certificates; Mutilated, Destroyed, Lost or Stolen Rights Certificates.
- ----------------------------------------------------------------------

                  (a) Subject to the provisions of Sections 7(e), 14 and 24
hereof, at any time after the Close of Business on the Distribution Date, and at
or prior to the Close of Business on the Expiration Date, any Rights Certificate
or Rights Certificates may be transferred, split up, combined or exchanged for
another Rights Certificate or Rights Certificates, entitling the registered
holder to purchase a like number of one-thousandths of a Preferred Share (or,
following a Triggering Event, other securities, cash or other assets, as the
case may be) as the Rights Certificate or Rights Certificates surrendered then
entitled such holder to purchase. Any registered holder desiring to transfer,
split up, combine or exchange any Rights Certificate or Rights Certificates
shall make such request in writing delivered to the Rights Agent, and shall
surrender the Rights Certificate or Rights Certificates to be transferred, split
up, combined or exchanged at the office of the Rights Agent designated for such
purpose. Neither the Rights Agent nor the Company shall be obligated to take any
action whatsoever with respect to the transfer of any such surrendered Rights
Certificate until the registered holder shall have completed and signed the
certificate contained in the form of assignment on the reverse side of such
Rights Certificate and shall have provided such additional evidence of the
identity of the 

                                      -8-
<PAGE>
 
Beneficial Owner (or former Beneficial Owner) or Affiliates or Associates
thereof as the Company shall reasonably request. Thereupon the Rights Agent
shall, subject to Sections 7(e), 14 and 24 hereof, countersign and deliver to
the person entitled thereto a Rights Certificate or Rights Certificates, as the
case may be, as so requested. The Company may require payment of a sum
sufficient to cover any tax or governmental charge that may be imposed in
connection with any transfer, split up, combination or exchange of Rights
Certificates.

                 (b) Upon receipt by the Company and the Rights Agent of
evidence reasonably satisfactory to them of the loss, theft, destruction or
mutilation of a Rights Certificate, and, in case of loss, theft or destruction,
of indemnity or security reasonably satisfactory to them, and, at the Company's
request, reimbursement to the Company and the Rights Agent of all reasonable
expenses incidental thereto, and upon surrender to the Rights Agent and
cancellation of the Rights Certificate if mutilated, the Company will make and
deliver a new Rights Certificate of like tenor to the Rights Agent for delivery
to the registered holder in lieu of the Rights Certificate so lost, stolen,
destroyed or mutilated.

         Section 7. Exercise of Rights; Purchase Price; Expiration Date of
                    ------------------------------------------------------
                    Rights.
                    ------

                 (a) Subject to Section 7(e) hereof, the registered holder of
any Rights Certificate may exercise the Rights evidenced thereby (except as
otherwise provided herein) in whole or in part at any time after the
Distribution Date upon surrender of the Rights Certificate, with the form of
election to purchase on the reverse side thereof duly executed, to the Rights
Agent at the office of the Rights Agent designated for such purpose, together
with payment of the Purchase Price for each one-thousandth of a Preferred Share
as to which the Rights are exercised, at or prior to the Expiration Date.

                 (b) The Purchase Price for each one-thousandth of a Preferred
Share issuable pursuant to the exercise of a Right shall initially be $60.00 and
shall be subject to adjustment from time to time as provided in Sections 11 and
13 hereof and shall be payable in lawful money of the United States of America
in accordance with paragraph (c) below.

                 (c) Upon receipt of a Rights Certificate representing
exercisable Rights, with the form of election to purchase duly executed,
accompanied by payment of the Purchase Price for the number of one-thousandths
of a Preferred Share (or other securities or property, as the case may be) to be
purchased and an amount equal to any applicable transfer tax required to be paid
by the holder of such Rights Certificate in accordance with Section 9 hereof in
cash, or by certified check or cashier's check payable to the order of the
Company, the Rights Agent shall, subject to Section 20(k) hereof, thereupon
promptly (i) (A) requisition from any transfer agent of the Preferred Shares (or
make available, if the Rights Agent is the transfer agent for the Preferred
Shares) a certificate or certificates for the number of one-thousandths of a
Preferred Share to be purchased and the Company hereby irrevocably authorizes
its transfer agent to comply with all such requests or (B) if the Company shall
have elected to deposit the total number of one-thousandths of a Preferred Share
issuable upon exercise of the Rights hereunder with a depository agent,
requisition from the depository agent of depository receipts representing such
number of one-thousandths of a Preferred Share as are to be purchased (in which
case certificates 

                                      -9-
<PAGE>
 
for the Preferred Shares represented by such receipts shall be deposited by the
transfer agent with the depository agent) and the Company hereby directs the
depository agent to comply with such request, (ii) when appropriate, requisition
from the Company the amount of cash to be paid in lieu of issuance of fractional
shares in accordance with Section 14 hereof, (iii) after receipt of such
certificates or depository receipts, cause the same to be delivered to or upon
the order of the registered holder of such Rights Certificate, registered in
such name or names as may be designated by such holder and (iv) when
appropriate, after receipt thereof, deliver such cash to or upon the order of
the registered holder of such Rights Certificate. The payment of the Purchase
Price (as such amount may be reduced (including to zero) pursuant to Section
11(a)(iv) hereof) may be made in cash or by certified check or cashier's check
payable to the order of the Company. In the event that the Company is obligated
to issue other securities of the Company, pay cash and/or distribute other
property pursuant to Section 11(a) hereof, the Company will make all
arrangements necessary so that such other securities, cash and/or other property
are available for distribution by the Rights Agent, if and when appropriate.


                 (d) In case the registered holder of any Rights Certificate
shall exercise less than all the Rights evidenced thereby, a new Rights
Certificate evidencing Rights equivalent to the Rights remaining unexercised
shall be issued by the Rights Agent to the registered holder of such Rights
Certificate or to his or her duly authorized assigns, subject to the provisions
of Section 14 hereof.

                 (e) Notwithstanding anything in this Agreement to the
contrary, from and after the first occurrence of a Triggering Event or a Section
13 Event, any Rights beneficially owned by (i) an Acquiring Person or an
Associate or Affiliate of an Acquiring Person, (ii) a transferee of an Acquiring
Person (or of any such Associate or Affiliate) who becomes a transferee after
the Acquiring Person becomes such (a "POST TRANSFEREE"), (iii) a transferee of
an Acquiring Person (or of any such Associate or Affiliate) who becomes a
transferee prior to or concurrently with the Acquiring Person becoming such and
receives such Rights pursuant to either (A) a transfer (whether or not for
consideration) from the Acquiring Person to holders of equity interests in such
Acquiring Person or to any Person with whom the Acquiring Person has any
continuing agreement, arrangement or understanding regarding the transferred
Rights or (B) a transfer which the Board of Directors of the Company has
determined is part of a plan, arrangement or understanding which has as a
primary purpose or effect the avoidance of this Section 7(e) (a "PRIOR
TRANSFEREE") or (iv) any subsequent transferee receiving transferred Rights from
a Post Transferee or a Prior Transferee, either directly or through one or more
intermediate transferees, shall become null and void without any further action
and no holder of such Rights shall have any rights whatsoever with respect to
such Rights, whether under any provision of this Agreement or otherwise. The
Company shall use all reasonable efforts to insure that the provisions of this
Section 7(e) and Section 4(b) hereof are complied with, but shall have no
liability to any holder of Rights Certificates or to any other Person as a
result of its failure to make any determinations with respect to an Acquiring
Person or any of such Acquiring Person's Affiliates, Associates or transferees
hereunder.

                 (f) Notwithstanding anything in this Agreement to the
contrary, neither the Rights Agent nor the Company shall be obligated to
undertake any action with respect to a 

                                     -10-
<PAGE>
 
registered holder upon the occurrence of any purported exercise as set forth in
this Section 7 unless such registered holder shall have (i) completed and signed
the certificate contained in the form of election to purchase set forth on the
reverse side of the Rights Certificate surrendered for such exercise and (ii)
provided such additional evidence of the identity of the Beneficial Owner (or
former Beneficial Owner) or Affiliates or Associates thereof as the Company
shall reasonably request.

         Section 8. Cancellation and Destruction of Rights Certificates. All
                    ---------------------------------------------------
Rights Certificates surrendered for the purpose of exercise, transfer, split up,
combination or exchange shall, if surrendered to the Company or to any of its
agents, be delivered to the Rights Agent for cancellation or in canceled form,
or, if surrendered to the Rights Agent, shall be canceled by it, and no Rights
Certificates shall be issued in lieu thereof except as expressly permitted by
any of the provisions of this Agreement. The Company shall deliver to the Rights
Agent for cancellation and retirement, and the Rights Agent shall so cancel and
retire, any other Rights Certificate purchased or acquired by the Company
otherwise than upon the exercise thereof. The Rights Agent shall deliver all
canceled Rights Certificates to the Company, or shall, at the written request of
the Company, destroy such canceled Rights Certificates, and in such case shall
deliver a certificate of destruction thereof to the Company.

         Section 9. Reservation and Availability of Preferred Shares.
                    ------------------------------------------------

                (a) The Company covenants and agrees that it will use its best
efforts to cause to be reserved and kept available out of and to the extent of
its authorized and unissued shares of Preferred Stock not reserved for another
purpose (and, following the occurrence of a Triggering Event, out of its
authorized and unissued shares of Common Stock and/or other securities), the
number of Preferred Shares (and, following the occurrence of the Triggering
Event, Common Stock and/or other securities) that will be sufficient to permit
the exercise in full of all outstanding Rights.

                (b) If the Company shall hereafter list any of its Preferred
Shares on a national securities exchange, then so long as the Preferred Shares
(and, following the occurrence of a Triggering Event, Common Shares and/or other
securities) issuable and deliverable upon exercise of the Rights may be listed
on a national securities exchange, the Company shall use its best efforts to
cause, from and after such time as the Rights become exercisable (but only to
the extent that it is reasonably likely that the Rights will be exercised), all
shares reserved for such issuance to be listed on such exchange upon official
notice of issuance upon such exercise.

                (c) The Company shall use its best efforts to (i) file, as
soon as practicable following the earliest date after the first occurrence of a
Triggering Event in which the consideration to be delivered by the Company upon
exercise of the Rights has been determined in accordance with Section 11(a)(iv)
hereof, or as soon as is required by law following the Distribution Date, as the
case may be, a registration statement under the Securities Act of 1933, as
amended (the "SECURITIES ACT"), with respect to the securities purchasable upon
exercise of the Rights on an appropriate form, (ii) cause such registration
statement to become effective as soon as practicable after such filing and (iii)
cause such registration statement to remain effective 

                                     -11-
<PAGE>
 
(with a prospectus at all times meeting the requirements of the Securities Act)
until the earlier of (A) the date as of which the Rights are no longer
exercisable for such securities and (B) the date of expiration of the Rights.
The Company may temporarily suspend, for a period not to exceed ninety (90) days
after the date set forth in clause (i) of the first sentence of this Section
9(c), the exercisability of the Rights in order to prepare and file such
registration statement and permit it to become effective. Upon any such
suspension, the Company shall issue a public announcement stating, and notify
the Rights Agent, that the exercisability of the Rights has been temporarily
suspended, as well as a public announcement and notification to the Rights Agent
at such time as the suspension is no longer in effect. The Company will also
take such action as may be appropriate under, or to ensure compliance with, the
securities or "blue sky" laws of the various states in connection with the
exercisability of the Rights. Notwithstanding any provision of this Agreement to
the contrary, the Rights shall not be exercisable in any jurisdiction, unless
the requisite qualification in such jurisdiction shall have been obtained, or an
exemption therefrom shall be available, and until a registration statement has
been declared effective.

                (d) The Company covenants and agrees that it will take all
such action as may be necessary to ensure that all Preferred Shares delivered
upon exercise of Rights shall, at the time of delivery of the certificates for
such Preferred Shares (subject to payment of the Purchase Price), be duly and
validly authorized and issued and fully paid and nonassessable shares.

                (e) The Company further covenants and agrees that it will pay
when due and payable any and all federal and state transfer taxes and charges
which may be payable in respect of the original issuance or delivery of the
Rights Certificates or of any Preferred Shares upon the exercise of Rights. The
Company shall not, however, be required to pay any transfer tax which may be
payable in respect of any transfer or delivery of Rights Certificates to a
person other than, or the issuance or delivery of certificates or depository
receipts for the Preferred Shares in a name other than that of, the registered
holder of the Rights Certificate evidencing Rights surrendered for exercise or
to issue or to deliver any certificates or depository receipts for Preferred
Shares upon the exercise of any Rights until any such tax shall have been paid
(any such tax being payable by the holder of such Rights Certificate at the time
of surrender) or until it has been established to the Company's satisfaction
that no such tax is due.

         Section 10. Preferred Shares Record Date. Each person in whose name any
                    -----------------------------
certificate for a number of one-thousandths of a Preferred Share is issued upon
the exercise of Rights shall for all purposes be deemed to have become the
holder of record of Preferred Shares represented thereby on, and such
certificate shall be dated, the date upon which the Rights Certificate
evidencing such Rights was duly surrendered and payment of the Purchase Price
multiplied by the number of one-thousandths of a Preferred Share with respect to
which the Rights have been exercised (and any applicable transfer taxes) was
made; provided, however, that if the date of such surrender and payment is a
      --------  -------
date upon which the Preferred Shares transfer books of the Company are closed,
such person shall be deemed to have become the record holder of such shares on,
and such certificate shall be dated, the next succeeding Business Day on which
the Preferred Shares transfer books of the Company are open. Prior to the
exercise of the Rights evidenced thereby, the holder of a Rights Certificate
shall not be entitled to any rights of a holder of Preferred Shares for which
the Rights shall be exercisable, including, without limitation, the 

                                     -12-
<PAGE>
 
right to vote, to receive dividends or other distributions or to exercise any
preemptive rights, and shall not be entitled to receive any notice of any
proceedings of the Company, except as provided herein.

         Section 11. Adjustment of Purchase Price, Number of Shares or Number of
                     -----------------------------------------------------------
Rights. The Purchase Price, the number and kind of shares or other property
- ------
covered by each Right and the number of Rights outstanding are subject to
adjustment from time to time as provided in this Section 11.

                (a) (i) In the event the Company shall at any time after the
date of this Agreement (A) declare a dividend on the Common Shares payable in
Common Shares, (B) subdivide the outstanding Common Shares, (C) combine the
outstanding Common Shares (by reverse stock split or otherwise) into a smaller
number of Common Shares, or (D) issue any shares of its capital stock in a
reclassification of the Common Shares (including any such reclassification in
connection with a consolidation or merger in which the Company is the continuing
or surviving corporation), then, in each such event, except as otherwise
provided in this Section 11(a) and Section 7(e) hereof: (1) each of the Rights
outstanding at the time of the record date for such dividend or the effective
date of such subdivision, combination or reclassification shall be
proportionately adjusted to that number of Rights (calculated to the nearest one
ten-thousandth (1/10,000) of a Right) equal to a fraction (the "EXCHANGE
RATIO"), the numerator of which shall be the total number of Common Shares or
shares of capital stock issued in such reclassification of the Common Shares
outstanding immediately following such time and the denominator of which shall
be the total number of Common Shares outstanding immediately prior to such time,
and the number of Rights that shall thereafter be issued with respect to each
Common Share or share of such other capital stock that shall become outstanding
thereafter prior to the Distribution Date shall be equal to the total number of
outstanding Rights immediately after such event (as adjusted pursuant to this
clause (1)) divided by the total number of outstanding Common Shares or shares
of such other capital stock immediately after such event (subject to further
adjustment pursuant to the provisions of this Agreement); (2) the Purchase Price
in effect at the time of the record date for such dividend or of the effective
date of such subdivision, combination or reclassification shall be adjusted so
that the Purchase Price thereafter shall equal the result obtained by dividing
the Purchase Price in effect immediately prior to such time by the Exchange
Ratio; provided, however, that in no event shall the consideration to be paid
       --------  -------
upon the exercise of one Right be less than the aggregate par value of the
shares of capital stock of the Company issuable upon exercise of such Right; and
(3) the number of Preferred Shares or shares of such other capital stock
issuable upon the exercise of each Right shall remain unchanged immediately
after such event, but, in the event of a reclassification, the kind of shares
issuable upon the exercise of each Right immediately after such reclassification
shall be adjusted to be the kind of shares of such other capital stock issued in
such reclassification, rather than Preferred Shares. If an event occurs which
would require an adjustment under both this Section 11(a)(i) and Section
11(a)(ii) hereof, the adjustment provided for in this Section 11(a)(i) shall be
in addition to, and shall be made prior to, any adjustment required pursuant to
Section 11(a)(ii) hereof.

                                     -13-
<PAGE>
 
                           (ii)     Subject to Section 24 of this Agreement, in
the event a Triggering Event shall have occurred, then promptly following such
Triggering Event, proper provision shall be made so that each holder of a Right,
except as provided in Section 7(e) hereof, shall thereafter have the right to
receive for each Right, upon exercise thereof in accordance with the terms of
this Agreement and payment of the then-current Total Exercise Price, in lieu of
a number of one-thousandths of a Preferred Share, such number of Common Shares
of the Company as shall equal the result obtained by multiplying the then-
current Purchase Price by the then number of one-thousandths of a Preferred
Share for which a Right was exercisable (or would have been exercisable if the
Distribution Date had occurred) immediately prior to the first occurrence of a
Triggering Event, and dividing that product by 50% of the current per share
market price (determined pursuant to Section 11(d) hereof) for Common Shares on
the date of occurrence of the Triggering Event (such number of shares being
hereinafter referred to as the "ADJUSTMENT SHARES").

                           (iii)    The right to buy Common Shares of the
Company pursuant to Section 11(a)(ii) hereof shall not arise as a result of any
Person becoming an Acquiring Person through an acquisition of Common Shares
pursuant to a Permitted Offer.

                           (iv)     In lieu of issuing Common Shares in
accordance with Section 11(a)(ii) hereof, the Company may, if the Board of
Directors determines that such action is necessary or appropriate and not
contrary to the interest of holders of Rights (and, in the event that the number
of Common Shares which are authorized by the Company's Certificate of
Incorporation but not outstanding or reserved for issuance for purposes other
than upon exercise of the Rights are not sufficient to permit the exercise in
full of the Rights, or if any necessary regulatory approval for such issuance
has not been obtained by the Company, the Company shall): (A) determine the
excess of (1) the value of the Common Shares issuable upon the exercise of a
Right (the "CURRENT VALUE") over (2) the Purchase Price (such excess, the
"SPREAD") and (B) with respect to each Right, make adequate provision to
substitute for such Common Shares, upon exercise of the Rights, (1) cash, (2) a
reduction in the Purchase Price, (3) other equity securities of the Company
(including, without limitation, shares or units of shares of any series of
Preferred Stock which the Board of Directors of the Company has deemed to have
the same value as Common Shares (such shares or units of shares of Preferred
Stock are herein called "COMMON STOCK EQUIVALENTS")), except to the extent that
the Company has not obtained any necessary stockholder or regulatory approval
for such issuance, (4) debt securities of the Company, except to the extent that
the Company has not obtained any necessary stockholder or regulatory approval
for such issuance, (5) other assets or (6) any combination of the foregoing,
having an aggregate value equal to the Current Value, where such aggregate value
has been determined by the Board of Directors of the Company based upon the
advice of a nationally recognized investment banking firm selected by the Board
of Directors of the Company; provided, however, if the Company shall not have
made adequate provision to deliver value pursuant to clause (B) above within
thirty (30) days following the later of (x) the first occurrence of a Triggering
Event and (y) the date on which the Company's right of redemption pursuant to
Section 23(a) expires (the later of (x) and (y) being referred to herein as the
"SECTION 11(A)(ii) TRIGGER DATE"), then the Company shall be obligated to
deliver, upon the surrender for exercise of a Right and without requiring
payment of the Purchase Price, Common Shares (to the extent 

                                     -14-
<PAGE>
 
available), except to the extent that the Company has not obtained any necessary
stockholder or regulatory approval for such issuance, and then, if necessary,
cash, which shares and/or cash have an aggregate value equal to the Spread. If
the Board of Directors of the Company shall determine in good faith that it is
likely that sufficient additional Common Shares could be authorized for issuance
upon exercise in full of the Rights or that any necessary regulatory approval
for such issuance will be obtained, the thirty (30) day period set forth above
may be extended to the extent necessary, but not more than ninety (90) days
after the Section 11(a)(ii) Trigger Date, in order that the Company may seek
stockholder approval for the authorization of such additional shares or take
action to obtain such regulatory approval (such period, as it may be extended,
the "SUBSTITUTION PERIOD"). To the extent that the Company determines that some
action need be taken pursuant to the first and/or second sentences of this
Section 11(a)(iv), the Company (x) shall provide, subject to Section 7(e)
hereof, that such action shall apply uniformly to all outstanding Rights and (y)
may suspend the exercisability of the Rights until the expiration of the
Substitution Period in order to seek any authorization of additional shares, to
take any action to obtain any required regulatory approval and/or to decide the
appropriate form of distribution to be made pursuant to such first sentence and
to determine the value thereof. In the event of any such suspension, the Company
shall issue a public announcement stating that the exercisability of the Rights
has been temporarily suspended, as well as a public announcement at such time as
the suspension is no longer in effect. For purposes of this Section 11(a)(iv),
the value of the Common Shares shall be the current per share market price (as
determined pursuant to Section 11(d) hereof) of the Common Shares on the Section
11(a)(ii) Trigger Date and the value of any "common stock equivalent" shall be
deemed to have the same value as the Common Shares on such date.

                (b) In case the Company shall, at any time after the date of
this Agreement, fix a record date for the issuance of rights, options or
warrants to all holders of Common Shares or of any class or series of Equivalent
Shares entitling such holders (for a period expiring within forty-five (45)
calendar days after such record date) to subscribe for or purchase Common Shares
or Equivalent Shares or securities convertible into Common Shares or Equivalent
Shares at a price per share (or having a conversion price per share, if a
security convertible into Common Shares or Equivalent Shares) less than the then
current per share market price of the Common Shares or Equivalent Shares (as
defined in Section 11(d)) on such record date, then, in each such case, the
Purchase Price to be in effect after such record date shall be determined by
multiplying the Purchase Price in effect immediately prior to such record date
by a fraction, the numerator of which shall be the number of Common Shares and
Equivalent Shares (if any) outstanding on such record date, plus the number of
Common Shares or Equivalent Shares, as the case may be, which the aggregate
offering price of the total number of Common Shares or Equivalent Shares, as the
case may be, so to be offered (and/or the aggregate initial conversion price of
the convertible securities so to be offered) would purchase at such current
market price, and the denominator of which shall be the number of Common Shares
and Equivalent Shares (if any) outstanding on such record date, plus the number
of additional Common Shares or Equivalent Shares, as the case may be, to be
offered for subscription or purchase (or into which the convertible securities
so to be offered are initially convertible). In case such subscription price may
be paid in a consideration part or all of which shall be in a form other than
cash, the value of such consideration shall be as determined in good faith by
the Board of Directors of the 

                                     -15-
<PAGE>
 
Company, whose determination shall be described in a statement filed with the
Rights Agent and shall be binding on the Rights Agent and the holders of the
Rights. Common Shares and Equivalent Shares owned by or held for the account of
the Company shall not be deemed outstanding for the purpose of any such
computation. Such adjustment shall be made successively whenever such a record
date is fixed, and in the event that such rights, options or warrants are not so
issued, the Purchase Price shall be adjusted to be the Purchase Price which
would then be in effect if such record date had not been fixed.

                (c) In case the Company shall, at any time after the date of
this Agreement, fix a record date for the making of a distribution to all
holders of the Common Shares or of any class or series of Equivalent Shares
(including any such distribution made in connection with a consolidation or
merger in which the Company is the continuing or surviving corporation) of
evidences of indebtedness or assets (other than a regular quarterly cash
dividend, if any, or a dividend payable in Common Shares) or subscription
rights, options or warrants (excluding those referred to in Section 11(b)),
then, in each such case, the Purchase Price to be in effect after such record
date shall be determined by multiplying the Purchase Price in effect immediately
prior to such record date by a fraction, the numerator of which shall be the
current market price (as determined pursuant to Section 11(d) hereof) of a
Common Share or an Equivalent Share on such record date, less the fair market
value (as determined in good faith by the Board of Directors of the Company,
whose determination shall be described in a statement filed with the Rights
Agent) of the portion of the cash, assets or evidences of indebtedness so to be
distributed or of such subscription rights or warrants applicable to a Common
Share or Equivalent Share, as the case may be, and the denominator of which
shall be such current market price (as determined pursuant to Section 11(d)
hereof) of a Common Share or Equivalent Share on such record date. Such
adjustments shall be made successively whenever such a record date is fixed, and
in the event that such distribution is not so made, the Purchase Price shall be
adjusted to be the Purchase Price which would have been in effect if such record
date had not been fixed.

                (d) For the purpose of any computation hereunder, other than
computations made pursuant to Section 11(a)(iv) hereof, the "CURRENT PER SHARE
MARKET PRICE" of any security (a "SECURITY" for the purpose of this Section
11(d)) on any date shall be deemed to be the average of the daily closing prices
per share of such Security for the thirty (30) consecutive Trading Days (as such
term is hereinafter defined) immediately prior to such date, and for purposes of
computations made pursuant to Section 11(a)(iv) hereof, the "current per share
market price" of any Security on any date shall be deemed to be the average of
the daily closing prices per share of such Security for the ten (10) consecutive
Trading Days immediately prior to such date; provided, however, that in the
                                             --------  -------
event that the current per share market price of the Security is determined
during a period following the announcement by the issuer of such Security of (i)
a dividend or distribution on such Security payable in shares of such Security
or securities convertible into such shares or (ii) any subdivision, combination
or reclassification of such Security, and prior to the expiration of the
requisite thirty (30) Trading Day or ten (10) Trading Day period, after the
ex-dividend date for such dividend or distribution, or the record date for such
subdivision, combination or reclassification, then, and in each such case, the
current per share market price shall be appropriately adjusted to reflect the
current market price per share equivalent of such Security. The closing price
for each day shall be the last sale price, regular 

                                     -16-
<PAGE>
 
way, or, in case no such sale takes place on such day, the average of the
closing bid and asked prices, regular way, in either case as reported in the
principal consolidated transaction reporting system with respect to securities
listed or admitted to trading on the New York Stock Exchange or, if the Security
is not listed or admitted to trading on the New York Stock Exchange, as reported
in the principal consolidated transaction reporting system with respect to
securities listed on the principal national securities exchange on which the
Security is listed or admitted to trading or, if the Security is not listed or
admitted to trading on any national securities exchange, the last sale price or,
if such last sale price is not reported, the average of the high bid and low
asked prices in the over-the-counter market, as reported by the National
Association of Securities Dealers, Inc. Automated Quotations System ("NASDAQ")
or such other system then in use, or, if on any such date the Security is not
quoted by any such organization, the average of the closing bid and asked prices
as furnished by a professional market maker making a market in the Security
selected by the Board of Directors of the Company. If on any such date no market
maker is making a market in the Common Shares, the fair value of such shares on
such date as determined in good faith by the Board of Directors of the Company
shall be used. The term "TRADING DAY" shall mean a day on which the principal
national securities exchange on which the Security is listed or admitted to
trading is open for the transaction of business or, if the Security is not
listed or admitted to trading on any national securities exchange, a Business
Day. If the Common Shares are not publicly held or so listed or traded, "current
per share market price" shall mean the fair value per share as determined in
good faith by the Board of Directors of the Company, whose determination shall
be described in a statement filed with the Rights Agent and shall be conclusive
for all purposes.

                (e) Anything herein to the contrary notwithstanding, no
adjustment in the Purchase Price shall be required unless such adjustment would
require an increase or decrease of at least 1% in the Purchase Price; provided,
                                                                      --------
however, that any adjustments which by reason of this Section 11(e) are not
- -------
required to be made shall be carried forward and taken into account in any
subsequent adjustment. All calculations under this Section 11 shall be made to
the nearest cent or to the nearest ten-thousandth of a Common Share or other
share or one hundred-thousandth of a Preferred Share, as the case may be.
Notwithstanding the first sentence of this Section 11(e), any adjustment
required by this Section 11 shall be made no later than the earlier of (i) three
(3) years from the date of the transaction which requires such adjustment or
(ii) the Expiration Date.

                (f) If as a result of an adjustment made pursuant to Section
11(a) or 13(a) hereof, the holder of any Right thereafter exercised shall become
entitled to receive any shares of capital stock other than Preferred Shares,
thereafter the number of such other shares so receivable upon exercise of any
Right and if required, the Purchase Price thereof, shall be subject to
adjustment from time to time in a manner and on terms as nearly equivalent as
practicable to the provisions with respect to the Common Shares contained in
Sections 11(a), (b), (c), (e), (h), (i), (j), (k), (1) and (m), and the
provisions of Sections 7, 9, 10, 13 and 14 with respect to the Preferred Shares
shall apply on like terms to any such other shares.

                (g) All Rights originally issued by the Company subsequent to
any adjustment made to the Purchase Price hereunder shall evidence the right to
purchase, at the adjusted 

                                     -17-
<PAGE>
 
Purchase Price, the number of one-thousandths of a Preferred Share purchasable
from time to time hereunder upon exercise of the Rights, all subject to further
adjustment as provided herein.

                (h) Unless the Company shall have exercised its election as
provided in Section 11(i), upon each adjustment of the Purchase Price as a
result of the calculations made in Section 11(b), each Right outstanding
immediately prior to the making of such adjustment shall thereafter evidence the
right to purchase, at the adjusted Purchase Price, that number of Preferred
Shares (calculated to the nearest one hundred-thousandth of a share) obtained by
(i) multiplying (x) the number of Preferred Shares covered by a Right
immediately prior to this adjustment, by (y) the Purchase Price in effect
immediately prior to such adjustment of the Purchase Price, and (ii) dividing
the product so obtained by the Purchase Price in effect immediately after such
adjustment of the Purchase Price.

                (i) The Company may elect on or after the date of any
adjustment of the Purchase Price as a result of the calculations made in Section
11(b) to adjust the number of Rights, in substitution for any adjustment in the
number of Preferred Shares purchasable upon the exercise of a Right. Each of the
Rights outstanding after such adjustment of the number of Rights shall be
exercisable for the number of one-thousandths of a Preferred Share for which a
Right was exercisable immediately prior to such adjustment. Each Right held of
record prior to such adjustment of the number of Rights shall become that number
of Rights (calculated to the nearest ten-thousandth) obtained by dividing the
Purchase Price in effect immediately prior to adjustment of the Purchase Price
by the Purchase Price in effect immediately after adjustment of the Purchase
Price. The Company shall make a public announcement of its election to adjust
the number of Rights, indicating the record date for the adjustment, and, if
known at the time, the amount of the adjustment to be made. This record date may
be the date on which the Purchase Price is adjusted or any day thereafter, but,
if the Rights Certificates have been issued, shall be at least ten (10) days
later than the date of the public announcement. If Rights Certificates have been
issued, upon each adjustment of the number of Rights pursuant to this Section
11(i), the Company shall, as promptly as practicable, cause to be distributed to
holders of record of Rights Certificates on such record date Rights Certificates
evidencing, subject to Section 14 hereof, the additional Rights to which such
holders shall be entitled as a result of such adjustment, or, at the option of
the Company, shall cause to be distributed to such holders of record in
substitution and replacement for the Rights Certificates held by such holders
prior to the date of adjustment, and upon surrender thereof, if required by the
Company, new Rights Certificates evidencing all the Rights to which such holders
shall be entitled after such adjustment. Rights Certificates so to be
distributed shall be issued, executed and countersigned in the manner provided
for herein (and may bear, at the option of the Company, the adjusted Purchase
Price) and shall be registered in the names of the holders of record of Rights
Certificates on the record date specified in the public announcement.

                (j) Irrespective of any adjustment or change in the Purchase
Price or the number of Preferred Shares issuable upon the exercise of the
Rights, the Rights Certificates theretofore and thereafter issued may continue
to express the Purchase Price per one one-thousandth of a Preferred Share and
the number of one-thousandths of a Preferred Share which were expressed in the
initial Rights Certificates issued hereunder.

                                     -18-
<PAGE>
 
                  (k) Before taking any action that would cause an adjustment
reducing the Purchase Price below the par or stated value, if any, of the number
of one-thousandths of a Preferred Share issuable upon exercise of the Rights,
the Company shall take any corporate action which may, in the opinion of its
counsel, be necessary in order that the Company may validly and legally issue as
fully paid and nonassessable shares such number of one-thousandths of a
Preferred Share at such adjusted Purchase Price.

                  (1) In any case in which this Section 11 shall require that an
adjustment in the Purchase Price be made effective as of a record date for a
specified event, the Company may elect to defer until the occurrence of such
event the issuing to the holder of any Right exercised after such record date of
the number of one-thousandths of a Preferred Share and other capital stock or
securities of the Company, if any, issuable upon such exercise over and above
the number of one-thousandths of a Preferred Share and other capital stock or
securities of the Company, if any, issuable upon such exercise on the basis of
the Purchase Price in effect prior to such adjustment; provided, however, that
                                                       --------  -------
the Company shall deliver to such holder a due bill or other appropriate
instrument evidencing such holder's right to receive such additional shares
(fractional or otherwise) upon the occurrence of the event requiring such
adjustment.

                  (m) Anything in this Section 11 to the contrary
notwithstanding, prior to the Distribution Date, the Company shall be entitled
to make such reductions in the Purchase Price, in addition to those adjustments
expressly required by this Section 11, as and to the extent that it in its sole
discretion shall determine to be advisable in order that any (i) consolidation
or subdivision of the Preferred or Common Shares, (ii) issuance wholly for cash
of any Preferred or Common Shares at less than the current market price, (iii)
issuance wholly for cash of Preferred or Common Shares or securities which by
their terms are convertible into or exchangeable for Preferred or Common Shares,
(iv) stock dividends or (v) issuance of rights, options or warrants referred to
in this Section 11, hereafter made by the Company to holders of its Preferred or
Common Shares shall not be taxable to such stockholders.

                  (n) The Company covenants and agrees that it shall not, at any
time after the Distribution Date, effect or permit to occur any Triggering Event
or Section 13 Event, if (i) at the time or immediately after such Triggering
Event or Section 13 Event there are any rights, warrants or other instruments or
securities outstanding or agreements in effect which would substantially
diminish or otherwise eliminate the benefits intended to be afforded by the
Rights or (ii) prior to, simultaneously with or immediately after such Section
13 Event, the stockholders of the Person who constitutes, or would constitute,
the "Principal Party" for purposes of Section 13(b) hereof shall have received a
distribution of Rights previously owned by such Person or any of its Affiliates
and Associates.

                  (o) The Company covenants and agrees that, after the
Distribution Date, it will not, except as permitted by Sections 23, 24 or 27
hereof, take (or permit to be taken) any action if at the time such action is
taken it is reasonably foreseeable that such action will diminish substantially
or otherwise eliminate the benefits intended to be afforded by the Rights.

                                     -19-
<PAGE>
 
                  (p) Anything in this Agreement to the contrary
notwithstanding, in the event the Company shall at any time after the date of
this Agreement (A) declare a dividend on the Preferred Shares payable in
Preferred Shares, (B) subdivide the outstanding Preferred Shares, (C) combine
the outstanding Preferred Shares (by reverse stock split or otherwise) into a
smaller number of Preferred Shares, or (D) issue any shares of its capital stock
in a reclassification of the Preferred Shares (including any such
reclassification in connection with a consolidation or merger in which the
Company is the continuing or surviving corporation), then, in each such event,
except as otherwise provided in this Section 11 and Section 7(e) hereof: (1)
each of the Rights outstanding at the time of the record date for such dividend
or the effective date of such subdivision, combination or reclassification shall
be proportionately adjusted to that number of Rights (calculated to the nearest
one ten-thousandth (1/10,000) of a Right) equal to a fraction (the "EXCHANGE
FRACTION"), the numerator of which shall be the total number of Preferred Shares
or shares of capital stock issued in such reclassification of the Preferred
Shares outstanding immediately following such time and the denominator of which
shall be the total number of Preferred Shares outstanding immediately prior to
such time, and the number of Rights that shall thereafter be issued with respect
to each Common Share or share of other capital stock that shall be issued in a
reclassification of the Common Shares prior to the Distribution Date shall be
equal to the total number of outstanding Rights immediately after such event (as
adjusted pursuant to this clause (1)) divided by the total number of outstanding
Common Shares or shares of such other capital stock immediately after such event
(subject to further adjustment pursuant to the provisions of this Agreement);
(2) the Purchase Price in effect at the time of the record date for such
dividend or of the effective date of such subdivision, combination or
reclassification shall be adjusted so that the Purchase Price thereafter shall
equal the result obtained by dividing the Purchase Price in effect immediately
prior to such time by the Exchange Fraction; provided, however, that in no event
                                             --------  -------
shall the consideration to be paid upon the exercise of one Right be less than
the aggregate par value of the shares of capital stock of the Company issuable
upon exercise of such Right; and (3) the number of one-thousandths of a
Preferred Share or share of such other capital stock issuable upon the exercise
of each Right shall remain unchanged immediately after such event, but, in the
event of a reclassification, the kind of shares issuable upon the exercise of
each Right immediately after such reclassification shall be adjusted to be the
kind of shares of such other capital stock issued in such reclassification,
rather than Preferred Shares.

         Section 12. Certificate of Adjusted Purchase Price or Number of Shares.
                     ----------------------------------------------------------
Whenever an adjustment is made as provided in Sections 11 and 13 hereof, the
Company shall promptly (a) prepare a certificate setting forth such adjustment
and a brief statement of the facts accounting for such adjustment, (b) file with
the Rights Agent and with each transfer agent for the Preferred Shares a copy of
such certificate and (c) mail a brief summary thereof to each holder of a Rights
Certificate in accordance with Section 26 hereof. Notwithstanding the foregoing
sentence, the failure of the Company to make such certification or give such
notice shall not affect the validity of such adjustment or the force or effect
of the requirement for such adjustment. The Rights Agent shall be fully
protected in relying on any such certificate and on any adjustment contained
therein and shall not be deemed to have knowledge of such adjustment unless and
until it shall have received such certificate.

         Section 13. Consolidation, Merger or Sale or Transfer of Assets or
                     ------------------------------------------------------
                     Earning Power.
                     -------------
                                     -20-
<PAGE>
 
                 (a)       In the event that, following the Shares Acquisition
Date, directly or indirectly:

                           (i)      the Company shall consolidate with, or merge
with and into, any other Person (other than a Subsidiary of the Company in a
transaction the principal purpose of which is to change the state of
incorporation of the Company or that complies with Section 11(o) hereof);

                           (ii)     any Person (other than a Subsidiary of the
Company in a transaction that complies with Section 11(o) hereof) shall
consolidate with the Company, or merge with and into the Company and the Company
shall be the continuing or surviving corporation of such consolidation or
merger; or

                           (iii)    the Company shall sell or otherwise transfer
(or one or more of its Subsidiaries shall sell or otherwise transfer), in one or
more transactions, assets or earning power aggregating 50% or more of the assets
or earning power of the Company and its Subsidiaries (taken as a whole) to any
other Person or Persons (other than the Company or one or more of its wholly
owned Subsidiaries in one or more transactions, each of which complies with
Section 11(o) hereof),

                                    then, and in each such case, proper
provision shall be made so that

                                    (A)     each holder of a Right (except as
otherwise provided herein) shall thereafter have the right to receive, upon the
exercise thereof in accordance with the terms of this Agreement, such number of
validly authorized and issued, fully paid and nonassessable Common Shares of the
Principal Party (as hereinafter defined), free of any liens, encumbrances,
rights of first refusal or other adverse claims, as shall be equal to the result
obtained by (1) multiplying the then current Purchase Price by the number of
one-thousandths of a Preferred Share for which a Right was exercisable
immediately prior to the first occurrence of a Section 13 Event (or, if a
Triggering Event has occurred prior to the first occurrence of a Section 13
Event, multiplying the number of such one-thousandths of a Preferred Share for
which a Right was exercisable immediately prior to the first occurrence of a
Triggering Event by the Purchase Price in effect immediately prior to such first
occurrence) and (2) dividing that product (which, following the first occurrence
of a Section 13 Event, shall be referred to as the "TOTAL EXERCISE PRICE" for
each Right and for all purposes of this Agreement) by 50% of the current per
share market price (determined pursuant to Section 11(d) hereof) of the Common
Shares of such Principal Party on the date of consummation of such Section 13
Event;

                                    (B)     such Principal Party shall
thereafter be liable for, and shall assume, by virtue of such Section 13 Event,
all the obligations and duties of the Company pursuant to this Agreement;

                                    (C)     the term "Company" shall thereafter
be deemed to refer to such Principal Party, it being specifically intended that
the provisions of Section 11 hereof shall apply only to such Principal Party
following the first occurrence of a Section 13 Event;

                                     -21-
<PAGE>
 
                                    (D)     such Principal Party shall take such
steps (including, but not limited to, the reservation of a sufficient number of
its Common Shares) in connection with the consummation of any such transaction
as may be necessary to assure that the provisions hereof shall thereafter be
applicable, as nearly as reasonably may be, in relation to its Common Shares
thereafter deliverable upon the exercise of the Rights.

                  (b) "PRINCIPAL PARTY" shall mean, in the case of any
transaction described in clause (i), (ii) or (iii) of Section 13(a), the Person
referred to therein or such Person's successor, including, if applicable, the
Company, if it is the surviving corporation), provided, however, that in any
                                              -----------------
such case, (i) if such Person is a direct or indirect Subsidiary of another
Person, "Principal Party" shall refer to such other Person and (ii) in case such
Person is a Subsidiary, directly or indirectly, of more than one Person,
"Principal Party" shall refer to whichever of such Persons is the issuer of the
Common Shares having the greatest aggregate value, and provided, further, that 
                                                       -----------------
for purposes of transactions described in clause (iii) hereof, "Principal Party"
shall refer to that Person receiving the greatest portion of the assets or
earning power transferred pursuant to such transaction or transactions.

                  (c) If, for any reason, the Rights cannot be exercised for
Common Shares of such Principal Party as provided in Section 13(a), then each
holder of Rights shall have the right to exchange its Rights for cash from such
Principal Party in an amount equal to the number of Common Shares that it would
otherwise be entitled to purchase times 50% of the current per share market
price, as determined pursuant to Section 11(d) hereof, of such Common Shares of
such Principal Party. If, for any reason, the foregoing formulation cannot be
applied to determine the cash amount into which the Rights are exchangeable,
then the Board of Directors, based upon the advice of one or more nationally
recognized investment banking firms, and based upon the total value of the
Company, shall determine such amount reasonably and with good faith to the
holders of Rights. Any such determination shall be final and binding on the
Rights Agent.

                  (d) Notwithstanding anything in this Agreement to the
contrary, Section 13 shall not be applicable to a transaction described in
clauses (i) and (ii) of Section 13(a) if: (i) such transaction is consummated
with a Person or Persons who acquired Common Shares pursuant to a Permitted
Offer (or a wholly-owned Subsidiary of any such Person or Persons); (ii) the
price per share of Common Shares offered in such transaction is not less than
the price per share of Common Shares paid to all holders of Common Shares whose
shares were purchased pursuant to such Permitted Offer; and (iii) the form of
consideration being offered to the remaining holders of Common Shares pursuant
to such transaction is the same form as the form of consideration paid pursuant
to such Permitted Offer. Upon consummation of any such transaction contemplated
by this Section 13(d), all Rights hereunder shall expire.

                  (e) The Company shall not consummate any Section 13 Event
unless the Principal Party shall have a sufficient number of authorized Common
Shares that have not been issued or reserved for issuance to permit the exercise
in full of the Rights in accordance with this Section 13 and unless prior
thereto the Company and such issuer shall have executed and delivered to the
Rights Agent a supplemental agreement confirming that such Principal Party

                                     -22-
<PAGE>
 
shall, upon consummation of such Section 13 Event, assume this Agreement in
accordance with Sections 13(a) and (b) hereof, that all rights of first refusal
or preemptive rights in respect of the issuance of Common Shares of such
Principal Party upon exercise of outstanding Rights have been waived, that there
are no rights, warrants, instruments or securities outstanding or any agreements
or arrangements which, as a result of the consummation of such transaction,
would eliminate or substantially diminish the benefits intended to be afforded
by the Rights and that such transaction shall not result in a default by such
Principal Party under this Agreement, and further providing that, as soon as
practicable after the date of such Section 13 Event, such Principal Party will:

                           (i)      prepare and file a registration statement
under the Securities Act with respect to the Rights and the securities
purchasable upon exercise of the Rights on an appropriate form, use its best
efforts to cause such registration statement to become effective as soon as
practicable after such filing and use its best efforts to cause such
registration statement to remain effective (with a prospectus at all times
meeting the requirements of the Securities Act) until the Expiration Date, and
similarly comply with applicable state securities laws;

                           (ii)     use its best efforts to list (or continue
the listing of) the Rights and the securities purchasable upon exercise of the
Rights on a national securities exchange or to meet the eligibility requirements
for quotation on Nasdaq; and

                           (iii)    deliver to holders of the Rights historical
financial statements for such Principal Party which comply in all respects with
the requirements for registration on Form 10 (or any successor form) under the
Exchange Act.

                           In the event that at any time after the occurrence of
a Triggering Event some or all of the Rights shall not have been exercised at
the time of a transaction described in this Section 13, the Rights which have
not theretofore been exercised shall thereafter be exercisable in the manner
described in Section 13(a) (without taking into account any prior adjustment
required by Section 11(a)(ii)).

                  (f) The provisions of this Section 13 shall similarly apply to
successive mergers or consolidations or sales or other transfers.

         Section 14. Fractional Rights and Fractional Shares.
                     ---------------------------------------

                 (a) The Company shall not be required to issue fractions of
Rights or to distribute Rights Certificates that evidence fractional Rights. In
lieu of such fractional Rights, there shall be paid to the registered holders of
the Rights Certificates with regard to which such fractional Rights would
otherwise be issuable, an amount in cash equal to the same fraction of the
current market value of a whole Right. For the purposes of this Section 14(a),
the current market value of a whole Right shall be the closing price of the
Rights for the Trading Day immediately prior to the date on which such
fractional Rights would have been otherwise issuable, as determined pursuant to
the second sentence of Section 11(d) hereof.


                                     -23-
<PAGE>
 
                 (b) The Company shall not be required to issue fractions of
Preferred Shares (other than fractions that are integral multiples of one
one-thousandth of a Preferred Share) upon exercise of the Rights or to
distribute certificates which evidence fractional Preferred Shares (other than
fractions that are integral multiples of one one-thousandth of a Preferred
Share). In lieu of fractional Preferred Shares that are not integral multiples
of one one-thousandth of a Preferred Share, the Company shall pay to the
registered holders of Rights Certificates at the time such Rights are exercised
as herein provided an amount in cash equal to the same fraction of the current
market value of a Common Share. For purposes of this Section 14(b), the current
market value of a Common Share shall be the closing price of a Common Share (as
determined pursuant to the second sentence of Section 11(d) hereof) for the
Trading Day immediately prior to the date of such exercise.

                 (c) The holder of a Right by the acceptance of the Right
expressly waives his or her right to receive any fractional Rights or any
fractional shares upon exercise of a Right.

         Section 15. Rights of Action. All rights of action in respect of this
                     ----------------
Agreement, excepting the rights of action given to the Rights Agent under
Section 18 hereof, are vested in the respective registered holders of the Rights
Certificates (and, prior to the Distribution Date, the registered holders of the
Common Shares); and any registered holder of any Rights Certificate (or, prior
to the Distribution Date, of the Common Shares), without the consent of the
Rights Agent or of the holder of any other Rights Certificate (or, prior to the
Distribution Date, of the Common Shares), may, in his or her own behalf and for
his or her own benefit, enforce, and may institute and maintain any suit, action
or proceeding against the Company to enforce, or otherwise act in respect of,
his or her right to exercise the Rights evidenced by such Rights Certificate in
the manner provided in such Rights Certificate and in this Agreement. Without
limiting the foregoing or any remedies available to the holders of Rights, it is
specifically acknowledged that the holders of Rights would not have an adequate
remedy at law for any breach of this Agreement and will be entitled to specific
performance of the obligations under, and injunctive relief against actual or
threatened violations of, the obligations of any Person subject to this
Agreement.

         Section 16. Agreement of Rights Holders.  Every holder of a
                     ---------------------------
Right, by accepting the same, consents and agrees with the Company and the
Rights Agent and with every other holder of a Right that:

                 (a) prior to the Distribution Date, the Rights will be
transferable only in connection with the transfer of the Common Shares;

                 (b) after the Distribution Date, the Rights Certificates are
transferable only on the registry books of the Rights Agent if surrendered at
the office or offices of the Rights Agent designated for such purposes, duly
endorsed or accompanied by a proper instrument of transfer and with the
appropriate forms and certificates fully executed; and

                 (c) subject to Sections 6(a) and 7(f) hereof, the Company and
the Rights Agent may deem and treat the person in whose name the Rights
Certificate (or, prior to the Distribution Date, the associated Common Shares
certificate) is registered as the absolute owner 

                                     -24-
<PAGE>
 
thereof and of the Rights evidenced thereby (notwithstanding any notations of
ownership or writing on the Rights Certificates or the associated Common Shares
certificate made by anyone other than the Company or the Rights Agent) for all
purposes whatsoever, and neither the Company nor the Rights Agent shall be
affected by any notice to the contrary.

         Section 17. Rights Certificate Holder Not Deemed a Stockholder. No
                     --------------------------------------------------
holder, as such, of any Rights Certificate shall be entitled to vote, receive
dividends or be deemed for any purpose the holder of the Preferred Shares or any
other securities of the Company which may at any time be issuable on the
exercise of the Rights represented thereby, nor shall anything contained herein
or in any Rights Certificate be construed to confer upon the holder of any
Rights Certificate, as such, any of the rights of a stockholder of the Company
or any right to vote for the election of directors or upon any matter submitted
to stockholders at any meeting thereof, or to give or withhold consent to any
corporate action, or to receive notice of meetings or other actions affecting
stockholders (except as provided in Section 25 hereof), or to receive dividends
or subscription rights, or otherwise, until the Right or Rights evidenced by
such Rights Certificate shall have been exercised in accordance with the
provisions hereof.

         Section 18. Concerning the Rights Agent.
                     ---------------------------

                 (a) The Company agrees to pay to the Rights Agent reasonable
compensation for all services rendered by it hereunder and, from time to time,
on demand of the Rights Agent, its reasonable expenses and counsel fees and
other disbursements incurred in the administration and execution of this
Agreement and the exercise and performance of its duties hereunder. The Company
also agrees to indemnify the Rights Agent for, and to hold it harmless against,
any loss, liability or expense, incurred without negligence, bad faith or
willful misconduct on the part of the Rights Agent, for anything done or omitted
by the Rights Agent in connection with the acceptance and administration of this
Agreement, including the costs and expenses of defending against any claim of
liability in the premises.

                 (b) The Rights Agent shall be protected and shall incur no
liability for, or in respect of any action taken, suffered or omitted by it in
connection with, its administration of this Agreement in reliance upon any
Rights Certificate or certificate for the Common Shares or for other securities
of the Company, instrument of assignment or transfer, power of attorney,
endorsement, affidavit, letter, notice, direction, consent, certificate,
statement or other paper or document believed by it to be genuine and to be
signed, executed and, where necessary, verified or acknowledged, by the proper
Person or Persons, or otherwise upon the advice of counsel as set forth in
Section 20 hereof.

         Section 19. Merger or Consolidation or Change of Name of Rights Agent.
                     ---------------------------------------------------------

                 (a) Any corporation into which the Rights Agent or any
successor Rights Agent may be merged or with which it may be consolidated, or
any corporation resulting from any merger or consolidation to which the Rights
Agent or any successor Rights Agent shall be a party, or any corporation
succeeding to the shareholder services business of the Rights Agent or any
successor Rights Agent, shall be the successor to the Rights Agent under this
Agreement without the execution or filing of any paper or any further act on the
part of any of the parties 

                                     -25-
<PAGE>
 
hereto; provided, however, that such corporation would be eligible for
        --------  -------
appointment as a successor Rights Agent under the provisions of Section 21
hereof. In case at the time such successor Rights Agent shall succeed to the
agency created by this Agreement, any of the Rights Certificates shall have been
countersigned but not delivered, any such successor Rights Agent may adopt the
countersignature of the predecessor Rights Agent and deliver such Rights
Certificates so countersigned; and in case at that time any of the Rights
Certificates shall not have been countersigned, any successor Rights Agent may
countersign such Rights Certificates either in the name of the predecessor
Rights Agent or in the name of the successor Rights Agent; and in all such cases
such Rights Certificates shall have the full force provided in the Rights
Certificates and in this Agreement.

                 (b) In case at any time the name of the Rights Agent shall be
changed and at such time any of the Rights Certificates shall have been
countersigned but not delivered, the Rights Agent may adopt the countersignature
under its prior name and deliver Rights Certificates so countersigned; and in
case at that time any of the Rights Certificates shall not have been
countersigned, the Rights Agent may countersign such Rights Certificates either
in its prior name or in its changed name; and in all such cases such Rights
Certificates shall have the full force provided in the Rights Certificates and
in this Agreement.

         Section 20. Duties of Rights Agent. The Rights Agent undertakes the
                     ----------------------
duties and obligations imposed by this Agreement upon the following terms and
conditions, by all of which the Company and the holders of Rights Certificates,
by their acceptance thereof, shall be bound:

                 (a) The Rights Agent may consult with legal counsel (who may
be legal counsel for the Company), and the opinion or advice of such counsel
shall be full and complete authorization and protection to the Rights Agent as
to any action taken or omitted by it in good faith and in accordance with such
opinion or advice.

                 (b) Whenever in the performance of its duties under this
Agreement the Rights Agent shall deem it necessary or desirable that any fact or
matter (including, without limitation, the identity of any Acquiring Person and
the determination of "current per share market price") be proved or established
by the Company prior to taking or suffering any action hereunder, such fact or
matter (unless other evidence in respect thereof be herein specifically
prescribed) may be deemed to be conclusively proved and established by a
certificate signed by any one of the Chairman of the Board, the Chief Executive
Officer, the President, any Vice President, the Chief Financial Officer, the
Secretary or any Assistant Secretary of the Company and delivered to the Rights
Agent; and such certificate shall be full authorization to the Rights Agent for
any action taken or suffered in good faith by it under the provisions of this
Agreement in reliance upon such certificate.

                 (c) The Rights Agent shall be liable hereunder to the Company
and any other Person only for its own negligence, bad faith or willful
misconduct; provided, however, that the Rights Agent shall not be liable for
special, indirect, incidental or consequential loss or damage.

                 (d) The Rights Agent shall not be liable for or by reason of
any of the statements of fact or recitals contained in this Agreement or in the
Rights Certificates (except its 

                                     -26-
<PAGE>
 
countersignature thereof) or be required to verify the same, but all such
statements and recitals are and shall be deemed to have been made by the Company
only.

                 (e) The Rights Agent shall not be under any responsibility in
respect of the validity of this Agreement or the execution and delivery hereof
(except the due execution hereof by the Rights Agent) or in respect of the
validity or execution of any Rights Certificate (except its countersignature
thereof); nor shall it be responsible for any breach by the Company of any
covenant or condition contained in this Agreement or in any Rights Certificate;
nor shall it be responsible for any change in the exercisability of the Rights
or any adjustment in the terms of the Rights (including the manner, method or
amount thereof) provided for in Sections 3, 11, 13, 23 or 24, or the
ascertaining of the existence of facts that would require any such change or
adjustment (except with respect to the exercise of Rights evidenced by Rights
Certificates after receipt by the Rights Agent of a certificate furnished
pursuant to Section 12 describing such change or adjustment); nor shall it by
any act hereunder be deemed to make any representation or warranty as to the
authorization or reservation of any Preferred Shares to be issued pursuant to
this Agreement or any Rights Certificate or as to whether any Preferred Shares
will, when issued, be validly authorized and issued, fully paid and
nonassessable.

                 (f) The Company agrees that it will perform, execute,
acknowledge and deliver or cause to be performed, executed, acknowledged and
delivered all such further and other acts, instruments and assurances as may
reasonably be required by the Rights Agent for the carrying out or performing by
the Rights Agent of the provisions of this Agreement.

                 (g) The Rights Agent is hereby authorized and directed to
accept instructions with respect to the performance of its duties hereunder from
any one of the Chief Executive Officer, the President, any Vice President, the
Chief Financial Officer, the Secretary or any Assistant Secretary of the
Company, and to apply to such officers for advice or instructions in connection
with its duties, and it shall not be liable for any action taken or suffered by
it in good faith in accordance with instructions of any such officer or for any
delay in acting while waiting for those instructions. Any application by the
Rights Agent for written instructions from the Company may, at the option of the
Rights Agent, set forth in writing any action proposed to be taken or omitted by
the Rights Agent under this Rights Agreement and the date on and/or after which
such action shall be taken or such omission shall be effective. The Rights Agent
shall not be liable for any action taken by, or omission of, the Rights Agent in
accordance with a proposal included in any such application on or after the date
specified in such application (which date shall not be less than five (5)
Business Days after the date any officer of the Company actually receives such
application, unless any such officer shall have consented in writing to an
earlier date) unless, prior to taking any such action (or the effective date in
the case of an omission), the Rights Agent shall have received written
instructions in response to such application specifying the action to be taken
or omitted.

                 (h) The Rights Agent and any stockholder, director, officer or
employee of the Rights Agent may buy, sell or deal in any of the Rights or other
securities of the Company or become pecuniarily interested in any transaction in
which the Company may be interested, or contract with or lend money to the
Company or otherwise act as fully and freely as though it 

                                     -27-
<PAGE>
 
were not Rights Agent under this Agreement. Nothing herein shall preclude the
Rights Agent from acting in any other capacity for the Company or for any other
legal entity.

                 (i) The Rights Agent may execute and exercise any of the
rights or powers hereby vested in it or perform any duty hereunder either itself
or by or through its attorneys or agents, and the Rights Agent shall not be
answerable or accountable for any act, default, neglect or misconduct of any
such attorneys or agents or for any loss to the Company resulting from any such
act, default, neglect or misconduct, provided reasonable care was exercised in
the selection and continued employment thereof.

                 (j) No provision of this Agreement shall require the Rights
Agent to expend or risk its own funds or otherwise incur any financial liability
in the performance of any of its duties hereunder or in the exercise of its
rights if there shall be reasonable grounds for believing that repayment of such
funds or adequate indemnification against such risk or liability is not
reasonably assured to it.

                 (k) If, with respect to any Rights Certificate surrendered to
the Rights Agent for exercise or transfer, the certificate attached to the form
of assignment or form of election to purchase, as the case may be, has either
not been completed or indicates an affirmative response to clause 1 and/or 2
thereof, the Rights Agent shall not take any further action with respect to such
requested exercise or transfer without first consulting with the Company.

         Section 21. Change of Rights Agent. The Rights Agent or any successor
                     ----------------------
Rights Agent may resign and be discharged from its duties under this Agreement
upon thirty (30) days' notice in writing mailed to the Company and to each
transfer agent of the Preferred Shares and the Common Shares by registered or
certified mail, and to the holders of the Rights Certificates by first-class
mail. The Company may remove the Rights Agent or any successor Rights Agent upon
thirty (30) days' notice in writing, mailed to the Rights Agent or successor
Rights Agent, as the case may be, and to each transfer agent of the Preferred
Shares and the Common Shares by registered or certified mail, and to the holders
of the Rights Certificates by first-class mail. If the Rights Agent shall resign
or be removed or shall otherwise become incapable of acting, the Company shall
appoint a successor to the Rights Agent. If the Company shall fail to make such
appointment within a period of thirty (30) days after giving notice of such
removal or after it has been notified in writing of such resignation or
incapacity by the resigning or incapacitated Rights Agent or by the holder of a
Rights Certificate (who shall, with such notice, submit his or her Rights
Certificate for inspection by the Company), then the registered holder of any
Rights Certificate may apply to any court of competent jurisdiction for the
appointment of a new Rights Agent. Any successor Rights Agent, whether appointed
by the Company or by such a court, shall be either (a) a corporation organized
and doing business under the laws of the United States or of any state of the
United States, in good standing, which is authorized under such laws to exercise
corporate trust or stockholder services powers and is subject to supervision or
examination by federal or state authority and which has at the time of its
appointment as Rights Agent a combined capital and surplus of at least $50
million or (b) an affiliate of such a corporation. After appointment, the
successor Rights Agent shall be vested with the same powers, rights, duties and
responsibilities as if it had been originally named as Rights Agent without
further act 

                                     -28-
<PAGE>
 
or deed; but the predecessor Rights Agent shall deliver and transfer to the
successor Rights Agent any property at the time held by it hereunder, and
execute and deliver any further assurance, conveyance, act or deed necessary for
the purpose. Not later than the effective date of any such appointment, the
Company shall file notice thereof in writing with the predecessor Rights Agent
and each transfer agent of the Preferred Shares and the Common Shares, and mail
a notice thereof in writing to the registered holders of the Rights
Certificates. Failure to give any notice provided for in this Section 21,
however, or any defect therein, shall not affect the legality or validity of the
resignation or removal of the Rights Agent or the appointment of the successor
Rights Agent, as the case may be.

         Section 22. Issuance of New Rights Certificates. Notwithstanding any of
                     -----------------------------------
the provisions of this Agreement or of the Rights to the contrary, the Company
may, at its option, issue new Rights Certificates evidencing Rights in such form
as may be approved by its Board of Directors to reflect any adjustment or change
in the Purchase Price and the number or kind or class of shares or other
securities or property purchasable under the Rights Certificates made in
accordance with the provisions of this Agreement. In addition, in connection
with the issuance or sale of Common Shares following the Distribution Date and
prior to the redemption or expiration of the Rights, the Company (a) shall, with
respect to Common Shares so issued or sold pursuant to the exercise of stock
options or under any employee plan or arrangement or upon the exercise,
conversion or exchange of the convertible subordinated debentures of the Company
outstanding at the date hereof or upon the exercise, conversion or exchange of
securities hereinafter issued by the Company and (b) may, in any other case, if
deemed necessary or appropriate by the Board of Directors of the Company, issue
Rights Certificates representing the appropriate number of Rights in connection
with such issuance or sale; provided, however, that (i) no such Rights
                            --------  -------
Certificate shall be issued and this sentence shall be null and void ab initio
                                                                     -- ------
if, and to the extent that, such issuance or this sentence would create a
significant risk of or result in material adverse tax consequences to the
Company or the Person to whom such Rights Certificate would be issued or would
create a significant risk of or result in such options' or employee plans' or
arrangements' failing to qualify for otherwise available special tax treatment
and (ii) no such Rights Certificate shall be issued if, and to the extent that,
appropriate adjustment shall otherwise have been made in lieu of the issuance
thereof.

         Section 23. Redemption.
                     ----------

                 (a) The Company may, at its option and with the approval of
the Board of Directors, at any time prior to the Close of Business on the
earlier of (i) the tenth day following the Shares Acquisition Date or such later
date as may be determined by action of a majority of Continuing Directors then
in office and publicly announced by the Company or (ii) the Final Expiration
Date, redeem all but not less than all the then outstanding Rights at a
redemption price of $.01 per Right, appropriately adjusted to reflect any stock
split, stock dividend or similar transaction occurring after the date hereof
(such redemption price being herein referred to as the "Redemption Price") and
the Company may, at its option, pay the Redemption Price either in Common Shares
(based on the current per share market price thereof (as determined pursuant to
Section 11(d) hereof) at the time of redemption) or cash; provided, however, if
                                                          --------  -------
the Board of Directors of the Company authorizes redemption of the Rights on or
after the time a Person 

                                     -29-
<PAGE>
 
becomes an Acquiring Person, then there must be Continuing Directors then in
office and such authorization shall require the concurrence of a majority of
such Continuing Directors.

                 (b) Immediately upon the action of the Board of Directors of
the Company ordering the redemption of the Rights, evidence of which shall have
been filed with the Rights Agent, and without any further action and without any
notice, the right to exercise the Rights will terminate and the only right
thereafter of the holders of Rights shall be to receive the Redemption Price.
Within ten (10) days after the action of the Board of Directors ordering the
redemption of the Rights, the Company shall give notice of such redemption to
the Rights Agent and the holders of the then outstanding Rights by mailing such
notice to all such holders at their last addresses as they appear upon the
registry books of the Rights Agent or, prior to the Distribution Date, on the
registry books of the transfer agent for the Common Shares. Any notice which is
mailed in the manner herein provided shall be deemed given, whether or not the
holder receives the notice. Each such notice of redemption will state the method
by which the payment of the Redemption Price will be made. Neither the Company
nor any of its Affiliates or Associates may redeem, acquire or purchase for
value any Rights at any time in any manner other than that specifically set
forth in this Section 23 or in Section 24 hereof, and other than in connection
with the purchase of Common Shares prior to the Distribution Date.

         Section 24. Exchange.
                     --------

                 (a) Subject to applicable laws, rules and regulations, and
subject to subsection (c) below, the Company may, at its option, by majority
vote of the Board of Directors and a majority vote of the Continuing Directors,
at any time after the occurrence of a Triggering Event, exchange all or part of
the then outstanding and exercisable Rights (which shall not include Rights that
have become void pursuant to the provisions of Section 7(e) hereof) for Common
Shares at an exchange ratio of one Common Share per Right, appropriately
adjusted to reflect any stock split, stock dividend or similar transaction
occurring after the date hereof (such exchange ratio being hereinafter referred
to as the "RATIO OF EXCHANGE"). Notwithstanding the foregoing, the Board of
Directors shall not be empowered to effect such exchange at any time after any
Person (other than the Company, any Subsidiary of the Company, any employee
benefit plan of the Company or any such Subsidiary, or any entity holding Common
Shares for or pursuant to the terms of any such plan), together with all
Affiliates and Associates of such Person, becomes the Beneficial Owner of 50% or
more of the Common Shares then outstanding.

                 (b) Immediately upon the action of the Board of Directors
ordering the exchange of any Rights pursuant to subsection (a) of this Section
24 and without any further action and without any notice, the right to exercise
such Rights shall terminate and the only right thereafter of a holder of such
Rights shall be to receive that number of Common Shares equal to the number of
such Rights held by such holder multiplied by the Ratio of Exchange. The Company
shall give public notice of any such exchange; provided, however, that the
                                               --------  -------
failure to give, or any defect in, such notice shall not affect the validity of
such exchange. The Company shall mail a notice of any such exchange to all of
the holders of such Rights at their last addresses as they appear upon the
registry books of the Rights Agent. Any notice which is mailed in the manner
herein provided shall be deemed given, whether or not the holder receives the
notice. 

                                     -30-
<PAGE>
 
Each such notice of exchange will state the method by which the exchange of the
Common Shares for Rights will be effected and, in the event of any partial
exchange, the number of Rights which will be exchanged. Any partial exchange
shall be effected pro rata based on the number of Rights (other than Rights
which have become void pursuant to the provisions of Section 7(e) hereof) held
by each holder of Rights.

                 (c) In the event that there shall not be sufficient Common
Shares issued but not outstanding or authorized but unissued to permit any
exchange of Rights as contemplated in accordance with Section 24(a), the Company
shall either take such action as may be necessary to authorize additional Common
Shares for issuance upon exchange of the Rights or alternatively, at the option
of a majority of the Board of Directors, with respect to each Right (i) pay cash
in an amount equal to the Current Value (as hereinafter defined), in lieu of
issuing Common Shares in exchange therefor, or (ii) issue debt or equity
securities or a combination thereof, having a value equal to the Current Value,
in lieu of issuing common Shares in exchange for each such Right, where the
value of such securities shall be determined by a nationally recognized
investment banking firm selected by the Board of Directors by majority vote of
the Board of Directors, or (iii) deliver any combination of cash, property,
Common Shares and/or other securities having a value equal to the Current Value
in exchange for each Right. For purposes of this Section 24(c) only, the Current
Value shall mean the product of the current per share market price of Common
Shares (determined pursuant to Section 11(d) on the date of the occurrence of
the event described above in subparagraph (a)) multiplied by the number of
Common Shares for which the Right otherwise would be exchangeable if there were
sufficient shares available. To the extent that the Company determines that some
action need be taken pursuant to clauses (i), (ii) or (iii) of this Section
24(c), the Board of Directors may temporarily suspend the exercisability of the
Rights for a period of up to sixty (60) days following the date on which the
event described in Section 24(a) shall have occurred, in order to seek any
authorization of additional Common Shares and/or to decide the appropriate form
of distribution to be made pursuant to the above provision and to determine the
value thereof. In the event of any such suspension, the Company shall issue a
public announcement stating that the exercisability of the Rights has been
temporarily suspended.

                 (d) The Company shall not be required to issue fractions of
Common Shares or to distribute certificates that evidence fractional Common
Shares. In lieu of such fractional Common Shares, there shall be paid to the
registered holders of the Rights Certificates with regard to which such
fractional Common Shares would otherwise be issuable, an amount in cash equal to
the same fraction of the current per share market value of a whole Common Share
(as determined pursuant to the second sentence of Section 11(d) hereof).

                 (e) The Company may, at its option, by majority vote of the
Board of Directors, at any time before any Person has become an Acquiring
Person, exchange all or part of the then outstanding Rights for rights of
substantially equivalent value, as determined reasonably and with good faith by
the Board of Directors, based upon the advice of one or more nationally
recognized investment banking firms.

                                     -31-
<PAGE>
 
                 (f) Immediately upon the action of the Board of Directors
ordering the exchange of any Rights pursuant to subsection (e) of this Section
24 and without any further action and without any notice, the right to exercise
such Rights shall terminate and the only right thereafter of a holder of such
Rights shall be to receive that number of rights in exchange therefor as has
been determined by the Board of Directors in accordance with subsection (e)
above. The Company shall give public notice of any such exchange; provided,
                                                                  --------
however, that the failure to give, or any defect in, such notice shall not
- -------
affect the validity of such exchange. The Company shall mail a notice of any
such exchange to all of the holders of such Rights at their last addresses as
they appear upon the registry books of the transfer agent for the Common Shares
of the Company. Any notice which is mailed in the manner herein provided shall
be deemed given, whether or not the holder receives the notice. Each such notice
of exchange will state the method by which the exchange of the Rights will be
effected.

         Section 25. Notice of Certain Events.
                     ------------------------

                 (a) In case the Company shall propose to effect or permit to
occur any Section 13 Event, the Company shall give notice thereof to each holder
of Rights in accordance with Section 26 hereof at least twenty (20) days prior
to occurrence of such Section 13 Event.

                 (b) In case any Triggering Event or Section 13 Event shall
occur, then, in any such case, the Company shall as soon as practicable
thereafter give to each holder of a Rights Certificate, in accordance with
Section 26 hereof, a notice of the occurrence of such event, which shall specify
the event and the consequences of the event to holders of Rights under Sections
11(a)(ii) and 13 hereof.

         Section 26. Notices. Notices or demands authorized by this Agreement to
                     -------
be given or made by the Rights Agent or by the holder of any Rights Certificate
to or on the Company shall be sufficiently given or made if sent by first-class
mail, postage prepaid, addressed (until another address is filed in writing with
the Rights Agent) as follows:

                                KeraVision, Inc.
                               48630 Milmont Drive
                                Fremont, CA 94538
                              Attention: President

Subject to the provisions of Section 21 hereof, any notice or demand authorized
by this Agreement to be given or made by the Company or by the holder of any
Rights Certificate to or on the Rights Agent shall be sufficiently given or made
if sent by first-class mail, postage prepaid addressed (until another address is
filed in writing with the Company) as follows:

                                     -32-
<PAGE>
 
                                BankBoston, N.A.
                             Blue Hills Office Park
                               Mail Stop 45-02-16
                                150 Royall Street
                                Canton, MA 02021
                       Attn: Shareholder Services Division

Notices or demands authorized by this Agreement to be given or made by the
Company or the Rights Agent to or on the holder of any Rights Certificate shall
be sufficiently given or made if sent by first-class mail, postage prepaid,
addressed to such holder at the address of such holder as shown on the registry
books of the Company.

         Section 27. Supplements and Amendments. Prior to the Distribution Date,
                     --------------------------
the Company may supplement or amend this Agreement in any respect without the
approval of any holders of Rights and the Rights Agent shall, if the Company so
directs, execute such supplement or amendment. From and after the Distribution
Date, the Company and the Rights Agent may from time to time supplement or amend
this Agreement without the approval of any holders of Rights in order to (i)
cure any ambiguity, (ii) correct or supplement any provision contained herein
which may be defective or inconsistent with any other provisions herein, (iii)
shorten or lengthen any time period hereunder (which lengthening or shortening,
following the first occurrence of an event set forth in clauses (i) and (ii) of
the proviso to Section 23(a) hereof, shall be effective only if there are
Continuing Directors and shall require the concurrence of a majority of such
Continuing Directors) or (iv) to change or supplement the provisions hereunder
in any manner that the Company may deem necessary or desirable and that shall
not adversely affect the interests of the holders of Rights (other than an
Acquiring Person or an Affiliate or Associate of an Acquiring Person); provided,
                                                                       --------
this Agreement may not be supplemented or amended to lengthen, pursuant to
clause (iii) of this sentence, (A) a time period relating to when the Rights may
be redeemed at such time as the Rights are not then redeemable or (B) any other
time period unless such lengthening is for the purpose of protecting, enhancing
or clarifying the rights of, and/or the benefits to, the holders of Rights. Upon
the delivery of a certificate from an appropriate officer of the Company that
states that the proposed supplement or amendment is in compliance with the terms
of this Section 27, the Rights Agent shall execute such supplement or amendment.
Prior to the Distribution Date, the interests of the holders of Rights shall be
deemed coincident with the interests of the holders of Common Shares.

         Section 28. Successors.  All the covenants and provisions of this
                     ----------
Agreement by or for the benefit of the Company or the Rights Agent shall bind
and inure to the benefit of their respective successors and assigns hereunder.

         Section 29. Determinations and Actions by the Board of Directors, etc.
                     ---------------------------------------------------------
For all purposes of this Agreement, any calculation of the number of Common
Shares outstanding at any particular time, including for purposes of determining
the particular percentage of such outstanding Common Shares of which any Person
is the Beneficial Owner, shall be made in accordance with the last sentence of
Rule 13d-3(d)(1)(i) of the General Rules and Regulations under the Exchange Act.
The Board of Directors of the Company (and, where specifically 

                                     -33-
<PAGE>
 
provided for herein, the Continuing Directors) shall have the exclusive power
and authority to administer this Agreement and to exercise all rights and powers
specifically granted to the Board, or the Company (or, where specifically
provided for herein, the Continuing Directors), or as may be necessary or
advisable in the administration of this Agreement, including, without
limitation, the right and power to (i) interpret the provisions of this
Agreement and (ii) make all determinations deemed necessary or advisable for the
administration of this Agreement (including a determination to redeem or not
redeem the Rights or to amend the Agreement). All such actions, calculations,
interpretations and determinations (including, for purposes of clause (y) below,
all omissions with respect to the foregoing) which are done or made by the Board
(or, where specifically provided for herein, by the Continuing Directors) in
good faith, shall (x) be final, conclusive and binding on the Company, the
Rights Agent, the holders of the Rights Certificates and all other parties and
(y) not subject the Board or the Continuing Directors to any liability to the
holders of the Rights.

         Section 30. Benefits of this Agreement.
                     --------------------------

         Nothing in this Agreement shall be construed to give to any Person
other than the Company, the Rights Agent and the registered holders of the
Rights Certificates (and, prior to the Distribution Date, the Common Shares) any
legal or equitable right, remedy or claim under this Agreement; but this
Agreement shall be for the sole and exclusive benefit of the Company, the Rights
Agent and the registered holders of the Rights Certificates (and, prior to the
Distribution Date, the Common Shares).

         Section 31. Severability. If any term, provision, covenant or
                     ------------
restriction of this Agreement is held by a court of competent jurisdiction or
other authority to be invalid, void or unenforceable, the remainder of the
terms, provisions, covenants and restrictions of this Agreement shall remain in
full force and effect and shall in no way be affected, impaired or invalidated;
provided, however, that notwithstanding anything in this Agreement to the
- --------  -------
contrary, if any such term, provision, covenant or restriction is held by such
court or authority to be invalid, void or unenforceable and the Board of
Directors of the Company determines in its good faith judgment that severing the
invalid language from this Agreement would adversely affect the purpose or
effect of this Agreement, the right of redemption set forth in Section 23 hereof
shall be reinstated and shall not expire until the close of business on the
tenth day following the date of such determination by the Board of Directors.

         Section 32. Governing Law. This Agreement and each Right and each
                     -------------
Rights Certificate issued hereunder shall be deemed to be a contract made under
the laws of the State of Delaware and for all purposes shall be governed by and
construed in accordance with the laws of such State applicable to contracts to
be made and performed entirely within such State.

         Section 33. Counterparts.  This Agreement may be executed in any number
                     ------------
of counterparts and each of such counterparts shall for all purposes be deemed
to be an original, and all such counterparts shall together constitute but one
and the same instrument.

                                     -34-
<PAGE>
 
         Section 34. Descriptive Headings.  Descriptive headings of the several
Sections of this Agreement are inserted for convenience only and shall not
control or affect the meaning or construction of any of the provisions hereof.

         IN WITNESS WHEREOF, the parties hereto have caused this Preferred
Shares Rights Agreement to be duly executed as of the day and year first above
written.

                                   KERAVISION, INC.

                                       
                                   By:  /s/ Thomas M. Loarie
                                   Name:  Thomas M. Loarie
                                   Title:  President and Chief Executive Officer


                                   BANKBOSTON, N.A.


                                   By: /s/ Geoffrey D. Anderson
                                      ------------------------------
                                   Name: Geoffrey D. Anderson
                                      ------------------------------
                                   Title: Director
                                      ------------------------------




                                     -35-
<PAGE>
 
                                    EXHIBIT A

                CERTIFICATE OF DESIGNATION OF RIGHTS, PREFERENCES

                                AND PRIVILEGES OF

                     SERIES A PARTICIPATING PREFERRED STOCK

                                       OF

                                KERAVISION, INC.



Pursuant to Section 151 of the General Corporation Law of the State of Delaware

         We, Thomas M. Loarie and Michael W. Hall, the President and the
Secretary, respectively, of KeraVision, Inc., a corporation organized and
existing under the General Corporation Law of the State of Delaware, in
accordance with the provisions of Section 103 thereof, DO HEREBY CERTIFY:

         That pursuant to the authority conferred upon the Board of Directors by
the Certificate of Incorporation of the said Corporation, the said Board of
Directors on August 18, 1997 adopted the following resolution creating a series
of shares of Preferred Stock designated as Series A Participating Preferred
Stock:

         "RESOLVED, that pursuant to the authority vested in the Board of
Directors of the corporation by the Certificate of Incorporation, the Board of
Directors does hereby provide for the issue of a series of Preferred Stock,
$0.001 par value, of the Corporation, to be designated "Series A Participating
Preferred Stock", initially consisting of thirty thousand (30,000) shares and to
the extent that the designations, powers, preferences and relative and other
special rights and the qualifications, limitations and restrictions of the
Series A Participating Preferred Stock are not stated and expressed in the
Certificate of Incorporation, does hereby fix and herein state and express such
designations, powers, preferences and relative and other special rights and the
qualifications, limitations and restrictions thereof, as follows (all terms used
herein which are defined in the Certificate of Incorporation shall be deemed to
have the meanings provided therein):

         Section 1. Designation and Amount. The shares of such series shall be
                    ----------------------
designated as "Series A Participating Preferred Stock", par value $0.001 per
share, and the number of shares constituting such series shall be thirty
thousand (30,000).

         Section 2. Dividends and Distributions.
                    ---------------------------

                 (A) Subject to the prior and superior right of the holders of
any shares of any series of Preferred Stock ranking prior and superior to the
shares of Series A Participating Preferred Stock with respect to dividends, the
holders of shares of Series A Participating 
<PAGE>
 
Preferred Stock shall be entitled to receive when, as and if declared by the
Board of Directors out of funds legally available for the purpose, quarterly
dividends payable in cash on the last day of March, June, September and December
in each year (each such date being referred to herein as a "QUARTERLY DIVIDEND
PAYMENT DATE"), commencing on the first Quarterly Dividend Payment Date after
the first issuance of a share or fraction of a share of Series A Participating
Preferred Stock, in an amount per share (rounded to the nearest cent) equal to,
subject to the provision for adjustment hereinafter set forth, 1,000 times the
aggregate per share amount of all cash dividends, and 1,000 times the aggregate
per share amount (payable in kind) of all non-cash dividends or other
distributions other than a dividend payable in shares of Common Stock or a
subdivision of the outstanding shares of Common Stock (by reclassification or
otherwise), declared on the Common Stock of the Corporation (the "COMMON STOCK")
since the immediately preceding Quarterly Dividend Payment Date, or, with
respect to the first Quarterly Dividend Payment Date, since the first issuance
of any share or fraction of a share of Series A Participating Preferred Stock.
In the event the Corporation shall at any time after August 18, 1997 (the
"RIGHTS DECLARATION DATE") (i) declare any dividend on Common Stock payable in
shares of Common Stock, (ii) subdivide the outstanding Common Stock, or (iii)
combine the outstanding Common Stock into a smaller number of shares, then in
each such case the amount to which holders of shares of Series A Participating
Preferred Stock were entitled immediately prior to such event under the
preceding sentence shall be adjusted by multiplying such amount by a fraction,
the numerator of which is the number of shares of Common Stock outstanding
immediately after such event and the denominator of which is the number of
shares of Common Stock that were outstanding immediately prior to such event.

                 (B) The Corporation shall declare a dividend or distribution
on the Series A Participating Preferred Stock as provided in paragraph (A) above
immediately after it declares a dividend or distribution on the Common Stock
(other than a dividend payable in shares of Common Stock).

                 (C) Dividends shall begin to accrue and be cumulative on
outstanding shares of Series A Participating Preferred Stock from the Quarterly
Dividend Payment Date next preceding the date of issue of such shares of Series
A Participating Preferred Stock, unless the date of issue of such shares is
prior to the record date for the first Quarterly Dividend Payment Date, in which
case dividends on such shares shall begin to accrue from the date of issue of
such shares, or unless the date of issue is a Quarterly Dividend Payment Date or
is a date after the record date for the determination of holders of shares of
Series A Participating Preferred Stock entitled to receive a quarterly dividend
and before such Quarterly Dividend Payment Date, in either of which events such
dividends shall begin to accrue and be cumulative from such Quarterly Dividend
Payment Date. Accrued but unpaid dividends shall not bear interest. Dividends
paid on the shares of Series A Participating Preferred Stock in an amount less
than the total amount of such dividends at the time accrued and payable on such
shares shall be allocated pro rata on a share-by-share basis among all such
shares at the time outstanding. The Board of Directors may fix a record date for
the determination of holders of shares of Series A Participating Preferred Stock
entitled to receive payment of a dividend or distribution declared thereon,
which record date shall be no more than 30 days prior to the date fixed for the
payment thereof.


                                      -2-
<PAGE>
 
         Section 3. Voting Rights.  The holders of shares of Series A
                    -------------
Participating Preferred Stock shall have the following voting rights:

                 (A) Subject to the provision for adjustment hereinafter set
forth, each share of Series A Participating Preferred Stock shall entitle the
holder thereof to 1,000 votes on all matters submitted to a vote of the
stockholders of the Corporation. In the event the Corporation shall at any time
after the Rights Declaration Date (i) declare any dividend on Common Stock
payable in shares of Common Stock, (ii) subdivide the outstanding Common Stock,
or (iii) combine the outstanding Common Stock into a smaller number of shares,
then in each such case the number of votes per share to which holders of shares
of Series A Participating Preferred Stock were entitled immediately prior to
such event shall be adjusted by multiplying such number by a fraction, the
numerator of which is the number of shares of Common Stock outstanding
immediately after such event and the denominator of which is the number of
shares of Common Stock that were outstanding immediately prior to such event.

                 (B) Except as otherwise provided herein or by law, the holders
of shares of Series A Participating Preferred Stock and the holders of shares of
Common Stock shall vote together as one class on all matters submitted to a vote
of stockholders of the Corporation.

                 (C) Except as required by law, holders of Series A
Participating Preferred Stock shall have no special voting rights and their
consent shall not be required (except to the extent they are entitled to vote
with holders of Common Stock as set forth herein) for taking any corporate
action.

         Section 4. Certain Restrictions.
                    --------------------

                 (A) The Corporation shall not declare any dividend on, make
any distribution on, or redeem or purchase or otherwise acquire for
consideration any shares of Common Stock after the first issuance of a share or
fraction of a share of Series A Participating Preferred Stock unless
concurrently therewith it shall declare a dividend on the Series A Participating
Preferred Stock as required by Section 2 hereof.

                 (B) Whenever quarterly dividends or other dividends or
distributions payable on the Series A Participating Preferred Stock as provided
in Section 2 are in arrears, thereafter and until all accrued and unpaid
dividends and distributions, whether or not declared, on shares of Series A
Participating Preferred Stock outstanding shall have been paid in full, the
Corporation shall not:

                      (i)      declare or pay dividends on, make any other
distributions on, or redeem or purchase or otherwise acquire for consideration
any shares of stock ranking junior (either as to dividends or upon liquidation,
dissolution or winding up) to the Series A Participating Preferred Stock;

                      (ii)     declare or pay dividends on, make any other
distributions on any shares of stock ranking on a parity (either as to dividends
or upon liquidation, dissolution or winding up) with Series A Participating
Preferred Stock, except dividends paid ratably on the 

                                      -3-
<PAGE>
 
Series A Participating Preferred Stock and all such parity stock on which
dividends are payable or in arrears in proportion to the total amounts to which
the holders of all such shares are then entitled;

                      (iii)    redeem or purchase or otherwise acquire for
consideration shares of any stock ranking on a parity (either as to dividends or
upon liquidation, dissolution or winding up) with the Series A Participating
Preferred Stock, provided that the Corporation may at any time redeem, purchase
or otherwise acquire shares of any such parity stock in exchange for shares of
any stock of the Corporation ranking junior (either as to dividends or upon
dissolution, liquidation or winding up) to the Series A Participating Preferred
Stock;

                      (iv)     purchase or otherwise acquire for consideration
any shares of Series A Participating Preferred Stock, or any shares of stock
ranking on a parity with the Series A Participating Preferred Stock, except in
accordance with a purchase offer made in writing or by publication (as
determined by the Board of Directors) to all holders of such shares upon such
terms as the Board of Directors, after consideration of the respective annual
dividend rates and other relative rights and preferences of the respective
series and classes, shall determine in good faith will result in fair and
equitable treatment among the respective series or classes.

                 (C) The Corporation shall not permit any subsidiary of the
Corporation to purchase or otherwise acquire for consideration any shares of
stock of the Corporation unless the Corporation could, under paragraph (A) of
this Section 4, purchase or otherwise acquire such shares at such time and in
such manner.

         Section 5. Reacquired Shares. Any shares of Series A Participating
                    -----------------
Preferred Stock purchased or otherwise acquired by the Corporation in any manner
whatsoever shall be retired and canceled promptly after the acquisition thereof.
All such shares shall upon their cancellation become authorized but unissued
shares of Preferred Stock and may be reissued as part of a new series of
Preferred Stock to be created by resolution or resolutions of the Board of
Directors, subject to the conditions and restrictions on issuance set forth
herein.

         Section 6. Liquidation, Dissolution or Winding Up.
                    --------------------------------------

                 (A) Upon any liquidation (voluntary or otherwise), dissolution
or winding up of the Corporation, no distribution shall be made to the holders
of shares of stock ranking junior (either as to dividends or upon liquidation,
dissolution or winding up) to the Series A Participating Preferred Stock unless,
prior thereto, the holders of shares of Series A Participating Preferred Stock
shall have received an amount equal to accrued and unpaid dividends and
distributions thereon, whether or not declared, to the date of such payment,
plus an amount equal to the greater of (1) $1,000 per share, provided that in
the event the Corporation does not have sufficient assets, after payment of its
liabilities and distribution to holders of Preferred Stock ranking prior to the
Series A Participating Preferred Stock, available to permit payment in full of
the $1,000 per share amount, the amount required to be paid under this Section
6(A)(1) shall, subject to Section 6(B) hereof, equal the value of the amount of
available assets divided by the number of outstanding shares of Series A
Participating Preferred Stock or (2) subject to the provisions for adjustment
hereinafter set forth, 1,000 times the aggregate per share amount to be

                                      -4-
<PAGE>
 
distributed to the holders of Common Stock (the greater of (1) or (2), the
"Series A Liquidation Preference"). In the event the Corporation shall at any
time after the Rights Declaration Date (i) declare any dividend on Common Stock
payable in shares of Common Stock, (ii) subdivide the outstanding Common Stock,
or (iii) combine the outstanding Common Stock into a smaller number of shares,
then in each such case the amount to which holders of shares of Series A
Participating Preferred Stock were entitled immediately prior to such event
under clause (2) of the preceding sentence shall be adjusted by multiplying such
amount by a fraction, the numerator of which is the number of shares of Common
Stock that were outstanding immediately after such event and the denominator of
which is the number of shares of Common Stock that were outstanding immediately
prior to such event.

                 (B) In the event, however, that there are not sufficient
assets available to permit payment in full of the Series A Liquidation
Preference and the liquidation preferences of all other series of Preferred
Stock, if any, which rank on a parity with the Series A Participating Preferred
Stock, then such remaining assets shall be distributed ratably to the holders of
such parity shares in proportion to their respective liquidation preferences.

         Section 7. Consolidation, Merger, etc. In case the Corporation shall
                    --------------------------
enter into any consolidation, merger, combination or other transaction in which
the shares of Common Stock are exchanged for or changed into other stock or
securities, cash and/or any other property, then in any such case the shares of
Series A Participating Preferred Stock shall at the same time be similarly
exchanged or changed in an amount per share (subject to the provision for
adjustment hereinafter set forth) equal to 1,000 times the aggregate amount of
stock, securities, cash and/or any other property (payable in kind), as the case
may be, into which or for which each share of Common Stock is changed or
exchanged. In the event the Corporation shall at any time after the Rights
Declaration Date (i) declare any dividend on Common Stock payable in shares of
Common Stock, (ii) subdivide the outstanding Common Stock, or (iii) combine the
outstanding Common Stock into a smaller number of shares, then in each such case
the amount set forth in the preceding sentence with respect to the exchange or
change of shares of Series A Participating Preferred Stock shall be adjusted by
multiplying such amount by a fraction, the numerator of which is the number of
shares of Common Stock outstanding immediately after such event and the
denominator of which is the number of shares of Common Stock that were
outstanding immediately prior to such event.

         Section 8. No Redemption.  The shares of Series A Participating
                    -------------
Preferred Stock shall not be redeemable.

         Section 9. Ranking. The Series A Participating Preferred Stock shall
                    -------
rank junior to all other series of the Corporation's Preferred Stock as to the
payment of dividends and the distribution of assets, unless the terms of any
such series shall provide otherwise.

         Section 10. Amendment. The Certificate of Incorporation of the
                     ----------
Corporation shall not be further amended in any manner which would materially
alter or change the powers, preference or special rights of the Series A
Participating Preferred Stock so as to affect them adversely 

                                      -5-
<PAGE>
 
without the affirmative vote of the holders of a majority or more of the
outstanding shares of Series A Participating Preferred Stock, voting separately
as a class.

         Section 11. Fractional Shares. Series A Participating Preferred Stock
                     -----------------
may be issued in fractions of a share which shall entitle the holder, in
proportion to such holder's fractional shares, to exercise voting rights,
receive dividends, participate in distributions and to have the benefit of all
other rights of holders of Series A Participating Preferred Stock."

         IN WITNESS WHEREOF, we have executed and subscribed this Certificate
and do affirm the foregoing as true under the penalties of perjury this ____ day
of ______________, _____.



                                    ---------------------------------------
                                    President


ATTEST:



- ----------------------------------
Secretary




                                      -6-
<PAGE>
 
                                    EXHIBIT B

                           FORM OF RIGHTS CERTIFICATE

Certificate No. R-                                                 ______ Rights

         NOT EXERCISABLE AFTER AUGUST 17, 2007, OR EARLIER IF TERMINATED BY THE
         COMPANY. THE RIGHTS ARE SUBJECT TO REDEMPTION, AT THE OPTION OF THE
         COMPANY, AT $.01 PER RIGHT ON THE TERMS SET FORTH IN THE RIGHTS
         AGREEMENT. UNDER CERTAIN CIRCUMSTANCES, RIGHTS BENEFICIALLY OWNED BY AN
         ACQUIRING PERSON OR AN AFFILIATE OR ASSOCIATE OF AN ACQUIRING PERSON
         (AS SUCH TERMS ARE DEFINED IN THE RIGHTS AGREEMENT) AND ANY SUBSEQUENT
         HOLDER OF SUCH RIGHTS MAY BECOME NULL AND VOID. [THE RIGHTS REPRESENTED
         BY THIS RIGHTS CERTIFICATE ARE OR WERE BENEFICIALLY OWNED BY A PERSON
         WHO WAS OR BECAME AN ACQUIRING PERSON OR AN AFFILIATE OR ASSOCIATE OF
         AN ACQUIRING PERSON (AS SUCH TERMS ARE DEFINED IN THE RIGHTS
         AGREEMENT). ACCORDINGLY, THIS RIGHTS CERTIFICATE AND THE RIGHTS
         REPRESENTED HEREBY MAY BECOME NULL AND VOID IN THE CIRCUMSTANCES
         SPECIFIED IN SECTION 7(e) OF SUCH RIGHTS AGREEMENT.*]

RIGHTS CERTIFICATE

         This certifies that ________________________, or registered assigns, is
the registered owner of the number of Rights set forth above, each of which
entitles the owner thereof, subject to the terms, provisions and conditions of
the Preferred Shares Rights Agreement, dated as of August 18, 1997 (the "RIGHTS
AGREEMENT"), between KeraVision, Inc., a Delaware corporation (the "COMPANY"),
and BankBoston, N.A. (the "RIGHTS AGENT"), to purchase from the Company at any
time after the Distribution Date (as such term is defined in the Rights
Agreement) and prior to 5:00 P.M., Boston, Massachusetts time, on August 17,
2007, at the office of the Rights Agent designated for such purpose, or at the
office of its successor as Rights Agent, one one-thousandth (1/1,000) of a fully
paid non-assessable share of Series A Participating Preferred Stock (the
"PREFERRED SHARES"), of the Company, at a purchase price of $60.00 per
one-thousandth of a Preferred Share (the "PURCHASE PRICE"), upon presentation
and surrender of this Rights Certificate with the Form of Election to Purchase
and related Certificate duly executed. The number of Rights evidenced by this
Rights Certificate (and the number of one-thousandths of a Preferred Share which
may be purchased upon exercise hereof) set forth above, are the number and
Purchase Price as of _____________, 1997, based on the Preferred Shares as
constituted at such date. As provided in the Rights Agreement, the Purchase
Price and the number and kind of Preferred Shares or other securities which may
be purchased upon the 

- --------
* The portion of the legend in bracket shall be inserted only if applicable and
shall replace the preceding sentence.
<PAGE>
 
exercise of the Rights evidenced by this Rights Certificate are subject to
modification and adjustment upon the happening of certain events.

         This Rights Certificate is subject to all of the terms, provisions and
conditions of the Rights Agreement, which terms, provisions and conditions are
hereby incorporated herein by reference and made a part hereof and to which
Rights Agreement reference is hereby made for a full description of the rights,
limitations of rights, obligations, duties and immunities hereunder of the
Rights Agent, the Company and the holders of the Rights Certificates, which
limitations of rights include the temporary suspension of the exercisability of
such Rights under the specific circumstances set forth in the Rights Agreement.
Copies of the Rights Agreement are on file at the principal executive offices of
the Company and the above-mentioned office of the Rights Agent.

         Subject to the provisions of the Rights Agreement, the Rights evidenced
by this Rights Certificate (i) may be redeemed by the Company, at its option, at
a redemption price of $.01 per Right or (ii) may be exchanged by the Company in
whole or in part for Common Shares, substantially equivalent rights or other
consideration as determined by the Company.

         This Rights Certificate, with or without other Rights Certificates,
upon surrender at the office of the Rights Agent designated for such purpose,
may be exchanged for another Rights Certificate or Rights Certificates of like
tenor and date evidencing Rights entitling the holder to purchase a like
aggregate amount of securities as the Rights evidenced by the Rights Certificate
or Rights Certificates surrendered shall have entitled such holder to purchase.
If this Rights Certificate shall be exercised in part, the holder shall be
entitled to receive upon surrender hereof another Rights Certificate or Rights
Certificates for the number of whole Rights not exercised.

         No fractional portion less than integral multiples of one
one-thousandth of a Preferred Share will be issued upon the exercise of any
Right or Rights evidenced hereby but in lieu thereof a cash payment will be
made, as provided in the Rights Agreement.

         No holder of this Rights Certificate, as such, shall be entitled to
vote or receive dividends or be deemed for any purpose the holder of the
Preferred Shares or of any other securities of the Company which may at any time
be issuable on the exercise hereof, nor shall anything contained in the Rights
Agreement or herein be construed to confer upon the holder hereof, as such, any
of the rights of a stockholder of the Company or any right to vote for the
election of directors or upon any matter submitted to stockholders at any
meeting thereof, or to give or withhold consent to any corporate action, or to
receive notice of meetings or other actions affecting stockholders (except as
provided in the Rights Agreement), or to receive dividends or subscription
rights, or otherwise, until the Right or Rights evidenced by this Rights
Certificate shall have been exercised as provided in the Rights Agreement.

         This Rights Certificate shall not be valid or obligatory for any
purpose until it shall have been countersigned by the Rights Agent.

                                      -2-
<PAGE>
 
         WITNESS the facsimile signature of the proper officers of the Company
and its corporate seal. Dated as of _______________ , 19__.



ATTEST:                                      KERAVISION, INC.



                                             By:
- ------------------------------------------       -------------------------------
       Secretary                                         President



Countersigned:

BankBoston, N.A.

- ------------------------------------------
as Rights Agent

By:
    --------------------------------------
         Authorized Signature



                                      -3-
<PAGE>
 
                   FORM OF REVERSE SIDE OF RIGHTS CERTIFICATE

                               FORM OF ASSIGNMENT

(To be executed by the registered holder if such holder desires to transfer 
 the Rights Certificate)



FOR VALUE RECEIVED_____________________________hereby sells, assigns
and transfers unto__________________________________________________________
(Please print name and address of transferee)
_____________________________________________________________________________
 this Rights Certificate, together with all right, title and interest therein,
and does hereby irrevocably constitute and appoint_____________________Attorney,
to transfer the Rights Certificate on the books of the within-named Company,
with full power of substitution.

Dated:______________________________________, 19__



                                    ___________________________________________
                                    Signature


Signature Guaranteed:

         Signatures must be guaranteed by a member firm of a registered national
securities exchange, a member of the National Association of Securities Dealers,
Inc., a commercial bank or trust company having an office or correspondent in
the United States or any other member of a medallion signature guarantee program
approved by the Securities Transfer Association.


                                      -4-
<PAGE>
 
                                   CERTIFICATE

The undersigned hereby certifies by checking the appropriate boxes that:

                  (1) this Rights Certificate [ ] is [ ] is not being sold,
assigned and transferred by or on behalf of a Person who is or was an Acquiring
Person, or an Affiliate or Associate of any such Person (as such terms are
defined in the Rights Agreement);

                  (2) after due inquiry and to the best knowledge of the
undersigned, it [ ] did [ ] did not acquire the Rights evidenced by this Rights
Certificate from any Person who is, was or subsequently became an Acquiring
Person or an Affiliate or Associate of any such Person. 
Dated:______________________________,____________


                                    ______________________________________
                                    Signature


Signature Guaranteed:

         Signatures must be guaranteed by a member firm of a registered national
securities exchange, a member of the National Association of Securities Dealers,
Inc., a commercial bank or trust company having an office or correspondent in
the United States or any other member of a medallion signature guarantee program
approved by the Securities Transfer Association.


                                      -5-
<PAGE>
 
             Form of Reverse Side of Rights Certificate -- continued

                          FORM OF ELECTION TO PURCHASE

       (To be executed if holder desires to exercise the Rights Certificate)



To:_____________________________________

         The undersigned hereby irrevocably elects to exercise________________
Rights represented by this Rights Certificate to purchase the number of one-
thousandths of a Preferred Share issuable upon the exercise of such Rights and
requests that certificates for such number of one-thousandths of a Preferred
Share be issued in the name of:

Please insert social security or other identifying number

_______________________________________________________________________________
 (Please print name and address)

_______________________________________________________________________________

If such number of Rights shall not be all the Rights evidenced by this Rights
Certificate, a new Rights Certificate for the balance shall be registered in the
name of and delivered to:

Please insert social security or other identifying number

_______________________________________________________________________________
 (Please print name and address)

_______________________________________________________________________________

Dated:___________________________,_____________



                                    ______________________________________
                                    Signature


Signature Guaranteed:

         Signatures must be guaranteed by a member firm of a registered national
securities exchange, a member of the National Association of Securities Dealers,
Inc., a commercial bank or trust company having an office or correspondent in
the United States or any other member of a medallion signature guarantee program
approved by the Securities Transfer Association.


                                      -6-
<PAGE>
 
                                   CERTIFICATE

         The undersigned hereby certifies by checking the appropriate boxes
that:

                  (1) the Rights evidenced by this Rights Certificate [ ] are
[ ] are not being exercised by or on behalf of a Person who is or was an
Acquiring Person or an Affiliate or Associate of any such Person (as such terms
are defined in the Rights Agreement);

                  (2) after due inquiry and to the best knowledge of the
undersigned, it [ ] did [ ] did not acquire the Rights evidenced by this Rights
Certificate from any Person who is, was or subsequently became an Acquiring
Person or an Affiliate or Associate of any such Person. 
Dated:_____________________________,_____________



                                    _______________________________________
                                    Signature

Signature Guaranteed:

         Signatures must be guaranteed by a member firm of a registered national
securities exchange, a member of the National Association of Securities Dealers,
Inc., a commercial bank or trust company having an office or correspondent in
the United States or any other member of a medallion signature guarantee program
approved by the Securities Transfer Association.



                                      -7-
<PAGE>
 
             Form of Reverse Side of Rights Certificate -- continued

                                     NOTICE

         The signature in the foregoing Forms of Assignment and Election must
conform to the name as written upon the face of this Rights Certificate in every
particular, without alteration or enlargement or any change whatsoever.




                                      -8-
<PAGE>
 
                                    EXHIBIT C

                                KERAVISION, INC.

                             STOCKHOLDER RIGHTS PLAN

                                SUMMARY OF RIGHTS


Distribution and Transfer of   The Board of Directors has declared a dividend
Rights; Rights Certificate:    of one Right for each share of Common Stock of 
- --------------------------     KeraVision, Inc. (the "COMPANY") outstanding.
                               Prior to the Distribution Date referred to below,
                               the Rights will be evidenced by and trade with
                               the certificates for the Common Stock. After the
                               Distribution Date, the Company will mail Rights
                               certificates to the Company's stockholders and
                               the Rights will become transferable apart from
                               the Common Stock.
                               
Distribution Date:             Rights will separate from the Common Stock and
- -----------------              become exercisable following the tenth day (or
                               such later date as may be determined by a
                               majority of the Directors not affiliated with the
                               acquiring person or group (the "CONTINUING
                               DIRECTORS") after a person or group (a) acquires
                               beneficial ownership of 20% or more of the
                               Company's Common Stock, or (b) announces a tender
                               or exchange offer, the consummation of which
                               would result in ownership by a person or group of
                               20% or more of the Company's Common Stock.

Preferred Stock Purchasable    After the Distribution Date, each Right will
Upon Exercise of Rights:       entitle the holder to purchase, for $60.00, a 
- -----------------------        fraction of a share of the Company's Preferred
                               Stock with economic terms similar to that of one
                               share of the Company's Common Stock.

Flip-In:                       If an acquiror (an "ACQUIRING PERSON") obtains
- -------                        20% or more of the Company's Common Stock (other
                               than pursuant to a tender offer deemed fair by
                               the Board of Directors (a "PERMITTED OFFER"),
                               then each Right (other than Rights owned by an
                               ----
                               Acquiring Person or its affiliates) will entitle
                               the holder thereof to purchase, for the exercise
                               price, a number of shares of the Company's Common
                               Stock having a then current market value of twice
                               the exercise price.
<PAGE>
 
Flip-Over:                     If, after the Shares Acquisition Date (defined 
- ---------                      below), (a) the Company merges into another 
                               entity (b) an acquiring entity merges into the
                               Company or (c) the Company sells more than 50% of
                               the Company's assets or earning power, then
                                                                      ----
                               each Right (other than Rights owned by an
                               Acquiring Person or its affiliates) will entitle
                               the holder thereof to purchase, for the exercise
                               price, a number of shares of Common Stock of the
                               person engaging in the transaction having a then
                               current market value of twice the exercise price
                               (unless the transaction satisfies certain
                               conditions and is consummated with a person who
                               acquired shares pursuant to a Permitted Offer, in
                               which case the Rights will expire).

Exchange Provision:            At any time after an event triggering the 
- ------------------             flip-in or flip-over rights and prior to the
                               acquisition by the Acquiring Person of 50% or
                               more of the outstanding Common Stock, the Board
                               of Directors of the Company may exchange the
                               Rights (other than Rights owned by the Acquiring
                               Person or its affiliates), in whole or in part,
                               at an exchange ratio of one share of Common Stock
                               per Right (subject to adjustment).

Redemption of                  Rights will be redeemable at the Company's  
the Rights:                    option for $0.01 per Right at any time on or 
- ----------                     prior to the tenth day (or such later date as 
                               may be determined by a majority of the Continuing
                               Directors) after public announcement that a
                               person has acquired beneficial ownership of 20%
                               or more of the Company's Common Stock (the
                               "SHARES ACQUISITION DATE").

Expiration of                  The Rights expire on the earliest of (a) August 
the Rights:                    17, 2007, (b) exchange or redemption of the
- ----------                     Rights as described above or (c) consummation
                               of a merger or consolidation or sale of assets
                               resulting in expiration of the Rights as
                               described above.

Amendment of Terms             The terms of the Rights and the Rights Agreement
of Rights:                     may be amended in any respect without the consent
- ---------                      of the Rights holders on or prior to the 
                               Distribution Date; thereafter, the terms of the
                               Rights and the Rights Agreement may be amended
                               without the consent of the Rights holders in
                               order to cure any ambiguities or to make changes
                               which do not adversely affect the interests of
                               Rights holders (other than the Acquiring Person).

Voting Rights:                 Rights will not have any voting rights.
- -------------

Anti-Dilution                  Rights will have the benefit of certain customary
Provisions:                    anti-dilution provisions.
- ----------
<PAGE>
 
Taxes:                         The Rights distribution should not be taxable for
- -----                          federal income tax purposes. However, following
                               an event which renders the Rights exercisable or
                               upon redemption of the Rights, stockholders may
                               recognize taxable income.

The foregoing is a summary of certain principal terms of the Stockholder Rights
Plan only and is qualified in its entirety by reference to the detailed terms of
the Rights Agreement dated as of August 18, 1997, between the Company and the
Rights Agent.

<PAGE>
 
                                                                   EXHIBIT 10.22
                          CHANGE OF CONTROL AGREEMENT


     This Change of Control Agreement (the "Agreement") is made and entered into
effective as of May 6, 1997, by and between Employee (the "Employee") and
KeraVision, Inc., a Delaware corporation (the "Company").

                                    RECITALS

     A.   It is expected that another company or other entity may from time to
time consider the possibility of acquiring the Company or that a change in
control may otherwise occur, with or without the approval of the Company's Board
of Directors (the "Board").  The Board recognizes that such consideration can be
a distraction to the Employee, a corporate officer of the Company, and can cause
the Employee to consider alternative employment opportunities.  The Board has
determined that it is in the best interests of the Company and its stockholders
to assure that the Company will have the continued dedication and objectivity of
the Employee, notwithstanding the possibility, threat or occurrence of a Change
of Control (as defined below) of the Company.

     B.   The Board believes that it is in the best interests of the Company and
its stockholders to provide the Employee with an incentive to continue his or
her employment with the Company, which for purposes of this Agreement as it
relates to Employee's employment shall include a majority-owned subsidiary of
the Company.

     C.   The Board believes that it is imperative to provide the Employee with
certain benefits upon a Change of Control and, under certain circumstances, upon
termination of the Employee's employment in connection with a Change of Control,
which benefits are intended to provide the Employee with financial security and
provide sufficient income and encouragement to the Employee to remain with the
Company notwithstanding the possibility of a Change of Control.

     D.   To accomplish the foregoing objectives, the Board of Directors has
directed the Company, upon execution of this Agreement by the Employee, to agree
to the terms provided in this Agreement.

     E.   Certain capitalized terms used in the Agreement are defined in
Section 4 below.

     In consideration of the mutual covenants contained in this Agreement, and
in consideration of the continuing employment of Employee by the Company, the
parties agree as follows:

          1.   At-Will Employment.  The Company and the Employee acknowledge
               ------------------                                           
that the Employee's employment is and shall continue to be at-will, as defined
under 

                                      -1-
<PAGE>
 
applicable law. If the Employee's employment terminates for any reason,
including (without limitation) any termination prior to a Change of Control, the
Employee shall not be entitled to any payments or benefits, other than as
provided by this Agreement, or as may otherwise be available in accordance with
the terms of the Company's established employee plans and written policies at
the time of termination. The terms of this Agreement shall terminate upon the
earlier of (i) the date on which Employee ceases to be employed as a corporate
officer of the Company, other than as a result of an involuntary termination by
the Company without Cause (ii) the date that all obligations of the parties
hereunder have been satisfied, or (iii) two (2) years after a Change of Control.
A termination of the terms of this Agreement pursuant to the preceding sentence
shall be effective for all purposes, except that such termination shall not
affect the payment or provision of compensation or benefits on account of a
termination of employment occurring prior to the termination of the terms of
this Agreement.

          2.   Stock Options.
               ------------- 

               (a) Hostile Takeover.  Subject to Sections 5 and 6 below, in the
                   ---------------- 
event of a Hostile Takeover and regardless of whether the Employee's employment
with the Company is terminated in connection with the Hostile Takeover, each
stock option granted for the Company's securities (the "Option") held by the
Employee shall become fully vested and immediately exercisable on the effective
date of the transaction and shall be exercisable to the extent so vested in
accordance with the provisions of the Option Agreement and Plan pursuant to
which such Option was granted.

               (b) Change of Control.  Subject to Sections 5 and 6 below, in the
                   -----------------
event of a Change of Control and regardless of whether the Employee's employment
with the Company is terminated in connection with the Change of Control, each
Option held by the Employee shall become vested on the effective date of the
transaction as to fifty percent (50%) of the Option shares that have not
otherwise vested as of such date.  The Option shares that remain unvested as of
the effective date of the transaction shall thereafter vest at the same rate
(that is, the same number of shares shall vest during each vesting period) that
was in effect prior to the Change of Control, and shall accordingly vest over a
period that is one-half of the total vesting period that would otherwise be then
remaining under the terms of the Option Agreement pursuant to which each such
Option was granted.

          3.   Change of Control.
               ----------------- 
               (a) Termination Following A Change of Control.  Subject to
                   -----------------------------------------   
Sections 5 and 6 below, if the Employee's employment with the Company is
terminated at any time within two (2) years after a Change of Control, then the
Employee shall be entitled to receive severance benefits as follows:

                        (i)   Voluntary Resignation.  If the Employee
                              --------------------- 
voluntarily resigns from the Company (other than as an Involuntary Termination
(as defined below) or if the Company terminates the Employee's employment for
Cause (as defined below)), then the Employee shall not be entitled to receive
severance payments. The Employee's benefits will be terminated under the
Company's then existing benefit plans and policies in accordance 

                                      -2-
<PAGE>
 
with such plans and policies in effect on the date of termination or as
otherwise determined by the Board of Directors of the Company.

                        (ii) Involuntary Termination.  If the Employee's
                             -----------------------
employment is terminated as a result of an Involuntary Termination other than
for Cause, the Employee shall be entitled to receive the following benefits:
(i) severance payments during the period from the date of the Employee's
termination until the date 12 months after the effective date of the termination
(the "Severance Period") equal to the salary which the Employee was receiving at
the time of such termination, which payments shall be paid during the Severance
Period in accordance with the Company's standard payroll practices; (ii) monthly
severance payments during the Severance Period equal to 1/12th of the Employee's
"target bonus" (as defined below) for the fiscal year in which the termination
occurs (or for the prior fiscal year if a target bonus has not yet been
determined for the fiscal year in which the termination occurs);
(iii) continuation of all health and life insurance benefits through the end of
the Severance Period substantially identical to those to which the Employee was
entitled immediately prior to the termination, or to those being offered to
officers of the Company, or a successor corporation, if the Company's benefit
programs are changed during the Severance Period; (iv) full and immediate
vesting of each unvested Option held by the Employee on the date of termination
so that each such option shall be exercisable in full on the termination date in
accordance with the provisions of the Option Agreement and Plan pursuant to
which such option was granted; and (v) outplacement services with a total value
not to exceed $15,000. For purposes of this Agreement, the term "target bonus"
shall mean the Employee's base salary in effect on the termination date
multiplied by that percentage of such base salary that is prescribed by the
Company under its Executive Bonus Program as the percentage of such base salary
payable to the Employee as a bonus if the Company pays bonuses at one-hundred
percent (100%) of its operating plan.

                        (iii) Involuntary Termination for Cause.  If the
                              ---------------------------------         
Employee's employment is terminated for Cause, then the Employee shall not be
entitled to receive severance payments.  The Employee's benefits will be
terminated under the Company's then existing benefit plans and policies in
accordance with such plans and policies in effect on the date of termination.

               (b) Termination Apart from A Change of Control.  In the event the
                   ------------------------------------------                   
Employee's employment terminates for any reason, either prior to the occurrence
of a Change of Control or after the two year period following the effective date
of a Change of Control, then the Employee shall not be entitled to receive any
severance payments under this Agreement.  The Employee's benefits will be
terminated under the terms of the Company's then existing benefit plans and
policies in accordance with such plans and policies in effect on the date of
termination or as otherwise determined by the Board of Directors of the Company.

          4.   Definition of Terms.  The following terms referred to in
               -------------------                                     
this Agreement shall have the following meanings:

                                      -3-
<PAGE>
 
               (a) Change of Control.  "Change of Control" shall mean the
                   -----------------                                     
occurrence of any of the following events:

                        (i)   Ownership.  Any "Person" (as such term is used in
                              --------- 
Sections 13(d) and 14(d) of the Securities Exchange Act of 1934, as amended) is
or becomes the "Beneficial Owner" (as defined in Rule 13d-3 under said Act),
directly or indirectly, of securities of the Company representing twenty percent
(20%) or more of the total voting power represented by the Company's then
outstanding voting securities without the approval of the Board of Directors of
the Company; or

                        (ii)  Merger/Sale of Assets.  A merger or consolidation
                              ---------------------         
of the Company whether or not approved by the Board of Directors of the Company,
other than a merger or consolidation which would result in the voting securities
of the Company outstanding immediately prior thereto continuing to represent
(either by remaining outstanding or by being converted into voting securities of
the surviving entity) at least fifty percent (50%) of the total voting power
represented by the voting securities of the Company or such surviving entity
outstanding immediately after such merger or consolidation, or the stockholders
of the Company approve a plan of complete liquidation of the Company or an
agreement for the sale or disposition by the Company of all or substantially all
of the Company's assets.

                        (iii) Change in Board Composition.  A change in the
                              ---------------------------                  
composition of the Board of Directors of the Company, as a result of which fewer
than a majority of the directors are Incumbent Directors.  "Incumbent Directors"
shall mean directors who either (A) are directors of the Company as of May 6,
1997 or (B) are elected, or nominated for election, to the Board of Directors of
the Company with the affirmative votes of at least a majority of the Incumbent
Directors at the time of such election or nomination (but shall not include an
individual whose election or nomination is in connection with an actual or
threatened proxy contest relating to the election of directors to the Company).

               (b) Cause.  "Cause" shall mean (i) gross negligence or willful
                   -----                                                     
misconduct in the performance of the Employee's duties to the Company where such
gross negligence or willful misconduct has resulted or is likely to result in
substantial and material damage to the Company or its subsidiaries,
(ii) repeated unexplained or unjustified absence from the Company, (iii) a
material and willful violation of any federal or state law; (iv) commission of
any act of fraud with respect to the Company; or (v) conviction of a felony or a
crime involving moral turpitude causing material harm to the standing and
reputation of the Company, in each case as determined in good faith by the Board
of Directors of the Company.

               (c) Hostile Takeover.  "Hostile Takeover" shall mean a
                   ---------------- 
transaction or series of transactions that results in any Person becoming the
Beneficial Owner, directly or indirectly, of securities of the Company
representing more than 50% of the total voting power represented by the
Company's then outstanding voting securities without the approval 
                                             -------

                                      -4-
<PAGE>
 
of the Board of Directors of the Company.

               (d) Involuntary Termination.  "Involuntary Termination" shall
                   -----------------------                     
include any termination by the Company other than for Cause and the Employee's
voluntary termination, upon 30 days prior written notice to the Company,
following (i) a material reduction or change in job duties, responsibilities and
requirements inconsistent with the Employee's position with the Company and the
Employee's prior duties, responsibilities and requirements; (ii) any reduction
of the Employee's base compensation (other than in connection with a general
decrease in base salaries for most similarly situated employees of the successor
corporation); or (iii) the Employee's refusal to relocate to a location more
than 50 miles from the Company's current location.

          5.   Limitation on Payments.
               ---------------------- 
               (a) In the event that the severance and other benefits provided
for in this Agreement to the Employee (i) constitute "parachute payments" within
the meaning of Section 280G of the Internal Revenue Code of 1986, as amended
(the "Code") and (ii) but for this Section, would be subject to the excise tax
imposed by Section 4999 of the Code, then the Employee's benefits under Sections
2 and 3(a)(ii) shall be payable either:

                        (i)   in full, or
          
                        (ii)  as to such lesser amount which would result in no
portion of such severance benefits being subject to excise tax under
Section 4999 of the Code, whichever of the foregoing amounts, taking into
account the applicable federal, state and local income taxes and the excise tax
imposed by Section 4999, results in the receipt by the Employee on an after-tax
basis, of the greatest amount of benefits under Sections 2 and 3(a)(ii),
notwithstanding that all or some portion of such benefits may be taxable under
Section 4999 of the Code. Unless the Company and the Employee otherwise agree in
writing, any determination required under this Section 5 shall be made in
writing by the Company's independent public accountants (the "Accountants"),
whose determination shall be conclusive and binding upon the Employee and the
Company for all purposes. For purposes of making the calculations required by
this Section 5, the Accountants may make reasonable assumptions and
approximations concerning applicable taxes and may rely on reasonable, good
faith interpretations concerning the application of Section 280G and 4999 of the
Code. The Company and the Employee shall furnish to the Accountants such
information and documents as the Accountants may reasonably request in order to
make a determination under this Section. The Company shall bear all costs the
Accountants may reasonably incur in connection with any calculations
contemplated by this Section 5.

               (b) The payment of severance and other benefits provided for in
this Agreement shall be subject to all applicable income, employment and social
tax rules and regulations.

          6.   Certain Business Combinations.  In the event it is determined by
               -----------------------------                                   
the 

                                      -5-
<PAGE>
 
Board, upon consultation with Company management and the Company's independent
auditors, that the enforcement of any Section of this Agreement, including, but
not limited to, Section 2 hereof, which allows for the acceleration of vesting
of Option shares upon the effective date of a Hostile Takeover or a Change of
Control, would preclude accounting for any proposed business combination of the
Company involving a Hostile Takeover or a Change of Control as a pooling of
interests, and the Board otherwise desires to approve such a proposed business
transaction which requires as a condition to the closing of such transaction
that it be accounted for as a pooling of interests, then any such Section of
this Agreement shall be null and void. For purposes of this Section 6, the
Board's determination shall require the unanimous approval of the non-employee
Board members.

          7.   Successors.  Any successor to the Company (whether direct or
               ----------                                                  
indirect and whether by purchase, lease, merger, consolidation, liquidation or
otherwise) to all or substantially all of the Company's business and/or assets
shall assume the obligations under this Agreement and agree expressly to perform
the obligations under this Agreement in the same manner and to the same extent
as the Company would be required to perform such obligations in the absence of a
succession.  The terms of this Agreement and all of the Employee's rights
hereunder shall inure to the benefit of, and be enforceable by, the Employee's
personal or legal representatives, executors, administrators, successors, heirs,
distributees, devisees and legatees.

          8.   Notice.  Notices and all other communications contemplated by
               ------                                                       
this Agreement shall be in writing and shall be deemed to have been duly given
when personally delivered or when mailed by U.S. registered or certified mail,
return receipt requested and postage prepaid.  Mailed notices to the Employee
shall be addressed to the Employee at the home address which the Employee most
recently communicated to the Company in writing.  In the case of the Company,
mailed notices shall be addressed to its corporate headquarters, and all notices
shall be directed to the attention of its Secretary.

          9.   Miscellaneous Provisions.
               ------------------------ 

               (a) No Duty to Mitigate.  The Employee shall not be required to
                   -------------------                                        
mitigate the amount of any payment contemplated by this Agreement (whether by
seeking new employment or in any other manner), nor, except as otherwise
provided in this Agreement, shall any such payment be reduced by any earnings
that the Employee may receive from any other source.

               (b) Waiver.  No provision of this Agreement shall be modified,
                   ------  
waived or discharged unless the modification, waiver or discharge is agreed to
in writing and signed by the Employee and by an authorized officer of the
Company (other than the Employee). No waiver by either party of any breach of,
or of compliance with, any condition or provision of this Agreement by the other
party shall be considered a waiver of any other condition or provision or of the
same condition or provision at another time.

               (c) Whole Agreement.  No agreements, representations or
                   --------------- 
understandings (whether oral or written and whether express or implied) which
are not 

                                      -6-
<PAGE>
 
expressly set forth in this Agreement have been made or entered into by either
party with respect to the subject matter hereof. This Agreement supersedes any
agreement of the same title and concerning similar subject matter dated prior to
the date of this Agreement, and by execution of this Agreement both parties
agree that any such predecessor agreement shall be deemed null and void.

               (d) Choice of Law.  The validity, interpretation, construction
                   ------------- 
and performance of this Agreement shall be governed by the laws of the State of
California without reference to conflict of laws provisions.

               (e) Severability.  If any term or provision of this Agreement or
the application thereof to any circumstance shall, in any jurisdiction and to
any extent, be invalid or unenforceable, such term or provision shall be
ineffective as to such jurisdiction to the extent of such invalidity or
unenforceability without invalidating or rendering unenforceable the remaining
terms and provisions of this Agreement or the application of such terms and
provisions to circumstances other than those as to which it is held invalid or
unenforceable, and a suitable and equitable term or provision shall be
substituted therefor to carry out, insofar as may be valid and enforceable, the
intent and purpose of the invalid or unenforceable term or provision.

               (f) Arbitration.  Any dispute or controversy arising under or in
                   -----------                                                 
connection with this Agreement may be settled at the option of either party by
binding arbitration in the County of Contra Costa, California, in accordance
with the rules of the American Arbitration Association then in effect.  Judgment
may be entered on the arbitrator's  award in any court having jurisdiction.
Punitive damages shall not be awarded.

               (g) Legal Fees and Expenses.  The parties shall each bear their
                   -----------------------  
own expenses, legal fees and other fees incurred in connection with this
Agreement.

               (h) No Assignment of Benefits.  The rights of any person to
                   -------------------------   
payments or benefits under this Agreement shall not be made subject to option or
assignment, either by voluntary or involuntary assignment or by operation of
law, including (without limitation) bankruptcy, garnishment, attachment or other
creditor's process, and any action in violation of this subsection (h) shall be
void.

               (i) Employment Taxes.  All payments made pursuant to this
                   ----------------   
Agreement will be subject to withholding of applicable income and employment
taxes.

               (j) Assignment by Company.  The Company may assign its rights
                   ---------------------    
under this Agreement to an affiliate, and an affiliate may assign its rights
under this Agreement to another affiliate of the Company or to the Company;
provided, however, that no assignment shall be made if the net worth of the
assignee is less than the net worth of the Company at the time of assignment. In
the case of any such assignment, the term "Company" when used in a section of
this Agreement shall mean the corporation that actually employs the Employee.

               (k) Counterparts.  This Agreement may be executed in
                   ------------  

                                      -7-
<PAGE>
 
counterparts, each of which shall be deemed an original, but all of which
together will constitute one and the same instrument.

                                      -8-
<PAGE>
 
     IN WITNESS WHEREOF, each of the parties has executed this Agreement, in the
case of the Company by its duly authorized officer, as of the day and year first
above written.


KERAVISION, INC.                        EMPLOYEE


By:                                     
    ______________________________      ______________________________      

Title:
      ____________________________

                                      -9-

<PAGE>
 
                                                                   EXHIBIT 10.23
 
                          CHANGE OF CONTROL AGREEMENT


     This Change of Control Agreement (the "Agreement") is made and entered into
effective as of May 6, 1997, by and between Thomas M. Loarie (the "Employee")
and KeraVision, Inc., a Delaware corporation (the "Company").

                                    RECITALS

     A.   It is expected that another company or other entity may from time to
time consider the possibility of acquiring the Company or that a change in
control may otherwise occur, with or without the approval of the Company's Board
of Directors (the "Board").  The Board recognizes that such consideration can be
a distraction to the Employee, a corporate officer of the Company, and can cause
the Employee to consider alternative employment opportunities.  The Board has
determined that it is in the best interests of the Company and its stockholders
to assure that the Company will have the continued dedication and objectivity of
the Employee, notwithstanding the possibility, threat or occurrence of a Change
of Control (as defined below) of the Company.

     B.   The Board believes that it is in the best interests of the Company and
its stockholders to provide the Employee with an incentive to continue his or
her employment with the Company.

     C.   The Board believes that it is imperative to provide the Employee with
certain benefits upon a Change of Control and, under certain circumstances, upon
termination of the Employee's employment in connection with a Change of Control,
which benefits are intended to provide the Employee with financial security and
provide sufficient income and encouragement to the Employee to remain with the
Company notwithstanding the possibility of a Change of Control.

     D.   To accomplish the foregoing objectives, the Board of Directors has
directed the Company, upon execution of this Agreement by the Employee, to agree
to the terms provided in this Agreement.

     E.   Certain capitalized terms used in the Agreement are defined in
Section 4 below.

     In consideration of the mutual covenants contained in this Agreement, and
in consideration of the continuing employment of Employee by the Company, the
parties agree as follows:

          1.   At-Will Employment.  The Company and the Employee acknowledge
               ------------------                                           
that the Employee's employment is and shall continue to be at-will, as defined
under applicable law. If the Employee's employment terminates for any reason,
including (without

                                      -1-
<PAGE>
 
limitation) any termination prior to a Change of Control, the
Employee shall not be entitled to any payments or benefits, other than as
provided by this Agreement, or as may otherwise be available in accordance with
the terms of Employee's Employment Agreement with the Company dated January 1,
1997 (the "Employment Agreement") the Company's established employee plans and
written policies at the time of termination. The terms of this Agreement shall
terminate upon the earlier of (i) the date on which Employee ceases to be
employed as a corporate officer of the Company, other than as a result of an
involuntary termination by the Company without Cause (ii) the date that all
obligations of the parties hereunder have been satisfied, or (iii) two (2) years
after a Change of Control. A termination of the terms of this Agreement pursuant
to the preceding sentence shall be effective for all purposes, except that such
termination shall not affect the payment or provision of compensation or
benefits on account of a termination of employment occurring prior to the
termination of the terms of this Agreement.

          2.   Stock Options.  Subject to Sections 5 and 6 below, in the event
               -------------                                                  
of a Change of Control and regardless of whether the Employee's employment with
the Company is terminated in connection with the Change of Control, each stock
option granted for the Company's securities (the "Options") held by the Employee
shall become fully vested and immediately exercisable on the effective date of
the transaction by the Option and shall be exercisable to the extent so vested
in accordance with the provisions of the Option Agreement and Plan pursuant to
which such option was granted.

          3.   Change of Control.
               ----------------- 

               (a)   Termination Following A Change of Control.  Subject to
                     -----------------------------------------      
Section 5 and 6 below, if the Employee's employment with the Company is
terminated at any time within two (2) years after a Change of Control, then the
Employee shall be entitled to receive severance benefits as follows:

                      (i)   Voluntary Resignation.  If the Employee voluntarily
                            ---------------------
resigns from the Company (other than as an Involuntary Termination (as defined
below) or if the Company terminates the Employee's employment for Cause (as
defined below)), then the Employee shall not be entitled to receive severance
payments. The Employee's benefits will be terminated under the terms of the
Employee Agreement and the Company's then existing benefit plans and policies in
accordance with such plans and policies in effect on the date of termination or
as otherwise determined by the Board of Directors of the Company.

                      (ii)  Involuntary Termination.  If the Employee's 
                            -----------------------    
employment is terminated as a result of an Involuntary Termination other than
for Cause, the Employee shall be entitled to receive the following benefits:
(i) severance payments during the period from the date of the Employee's
termination until the date 18 months after the effective date of the termination
(the "Severance Period") equal to the salary which the Employee was receiving at
the time of such termination, which payments shall be paid during the Severance
Period in accordance with the Company's standard payroll practices; (ii) monthly
severance payments during the Severance Period equal to 1/12th of the 

                                      -2-
<PAGE>
 
Employee's "target bonus" (as defined below) for the fiscal year in which the
termination occurs (or for the prior fiscal year if a target bonus has not yet
been determined for the fiscal year in which the termination occurs);
(iii) continuation of all health and life insurance benefits through the end of
the Severance Period substantially identical to those to which the Employee was
entitled immediately prior to the termination, or to those being offered to
officers of the Company, or a successor corporation, if the Company's benefit
programs are changed during the Severance Period; and (iv) outplacement services
with a total value not to exceed $15,000. For purposes of this Agreement, the
term "target bonus" shall mean the Employee's base salary in effect on the
termination date multiplied by that percentage of such base salary that is
prescribed by the Company under its Executive Bonus Program as the percentage of
such base salary payable to the Employee as a bonus if the Company pays bonuses
at one-hundred percent (100%) of its operating plan.

                      (iii) Involuntary Termination for Cause.  If the
                            ---------------------------------         
Employee's employment is terminated for Cause, then the Employee shall not be
entitled to receive severance payments. The Employee's benefits will be
terminated under the Company's then existing benefit plans and policies in
accordance with such plans and policies in effect on the date of termination.

               (b)   Termination Apart from A Change of Control.  In the event
                     ------------------------------------------ 
the Employee's employment terminates for any reason, either prior to the
occurrence of a Change of Control or after the two year period following the
effective date of a Change of Control, then the Employee shall not be entitled
to receive any severance payments under this Agreement. The Employee's benefits
will be terminated under the terms of the Employment Agreement and the Company's
then existing benefit plans and policies in accordance with such plans and
policies in effect on the date of termination or as otherwise determined by the
Board of Directors of the Company.

          4.   Definition of Terms.  The following terms referred to in this
               -------------------                                          
Agreement shall have the following meanings:

               (a) Change of Control.  "Change of Control" shall mean the
                   -----------------                                     
occurrence of any of the following events:

                      (i)   Ownership.  Any "Person" (as such term is used in
                            ---------
Sections 13(d) and 14(d) of the Securities Exchange Act of 1934, as amended) is
or becomes the "Beneficial Owner" (as defined in Rule 13d-3 under said Act),
directly or indirectly, of securities of the Company representing twenty percent
(20%) or more of the total voting power represented by the Company's then
outstanding voting securities without the approval of the Board of Directors of
                              -------
the Company; or

                      (ii)  Merger/Sale of Assets.  A merger or consolidation of
                            ---------------------   
the Company whether or not approved by the Board of Directors of the Company,
other than a merger or consolidation which would result in the voting securities
of the Company outstanding immediately prior thereto continuing to represent
(either by remaining outstanding or by being converted into voting securities of
the surviving entity) at least fifty 

                                      -3-
<PAGE>
 
percent (50%) of the total voting power represented by the voting securities of
the Company or such surviving entity outstanding immediately after such merger
or consolidation, or the stockholders of the Company approve a plan of complete
liquidation of the Company or an agreement for the sale or disposition by the
Company of all or substantially all of the Company's assets.

                      (iii) Change in Board Composition.  A change in the
                            ---------------------------                  
composition of the Board of Directors of the Company, as a result of which fewer
than a majority of the directors are Incumbent Directors.  "Incumbent Directors"
shall mean directors who either (A) are directors of the Company as of May 6,
1997 or (B) are elected, or nominated for election, to the Board of Directors of
the Company with the affirmative votes of at least a majority of the Incumbent
Directors at the time of such election or nomination (but shall not include an
individual whose election or nomination is in connection with an actual or
threatened proxy contest relating to the election of directors to the Company).

               (b) Cause.  "Cause" shall mean (i) gross negligence or willful
                   -----                                                     
misconduct in the performance of the Employee's duties to the Company where such
gross negligence or willful misconduct has resulted or is likely to result in
substantial and material damage to the Company or its subsidiaries,
(ii) repeated unexplained or unjustified absence from the Company, (iii) a
material and willful violation of any federal or state law; (iv) commsission of
any act of fraud with respect to the Company; or (v) conviction of a felony or a
crime involving moral turpitude causing material harm to the standing and
reputation of the Company, in each case as determined in good faith by the Board
of Directors of the Company.

               (c) Involuntary Termination.  "Involuntary Termination" shall
                   -----------------------    
include any termination by the Company other than for Cause and the Employee's
voluntary termination, upon 30 days prior written notice to the Company,
following (i) a material reduction or change in job duties, responsibilities and
requirements inconsistent with the Employee's position with the Company and the
Employee's prior duties, responsibilities and requirements; (ii) any reduction
of the Employee's base compensation (other than in connection with a general
decrease in base salaries for most similarly situated employees of the successor
corporation); or (iii) the Employee's refusal to relocate to a location more
than 50 miles from the Company's current location.

          5.   Limitation on Payments.  In the event that the severance and
               ----------------------                                      
other benefits provided for in this Agreement to the Employee (i) constitute
"parachute payments" within the meaning of Section 280G of the Internal Revenue
Code of 1986, as amended (the "Code") and (ii) but for this Section, would be
subject to the excise tax imposed by Section 4999 of the Code, then the
Employee's benefits under Sections 2 and 3(a)(ii) shall be payable either:

               (a)  in full, or

                                      -4-
<PAGE>
 
               (b) as to such lesser amount which would result in no portion of
such severance benefits being subject to excise tax under Section 4999 of the
Code, whichever of the foregoing amounts, taking into account the applicable
federal, state and local income taxes and the excise tax imposed by
Section 4999, results in the receipt by the Employee on an after-tax basis, of
the greatest amount of benefits under Sections 2 and 3(a)(ii), notwithstanding
that all or some portion of such benefits may be taxable under Section 4999 of
the Code. Unless the Company and the Employee otherwise agree in writing, any
determination required under this Section 5 shall be made in writing by the
Company's independent public accountants (the "Accountants"), whose
determination shall be conclusive and binding upon the Employee and the Company
for all purposes. For purposes of making the calculations required by this
Section 5, the Accountants may make reasonable assumptions and approximations
concerning applicable taxes and may rely on reasonable, good faith
interpretations concerning the application of Section 280G and 4999 of the Code.
The Company and the Employee shall furnish to the Accountants such information
and documents as the Accountants may reasonably request in order to make a
determination under this Section. The Company shall bear all costs the
Accountants may reasonably incur in connection with any calculations
contemplated by this Section 5.

          6.   Certain Business Combinations.  In the event it is determined by
               -----------------------------                                   
the Board, upon consultation with Company management and the Company's
independent auditors, that the enforcement of any Section of this Agreement,
including, but not limited to, Section 2 hereof, which allows for the
acceleration of vesting of Option shares upon the effective date of a Change of
Control, would preclude accounting for any proposed business combination of the
Company involving a Change of Control as a pooling of interests, and the Board
otherwise desires to approve such a proposed business transaction which requires
as a condition to the closing of such transaction that it be accounted for as a
pooling of interests, then any such Section of this Agreement shall be null and
void.  For purposes of this Section 6, the Board's determination shall require
the unanimous approval of the non-employee Board members.

          7.   Successors.  Any successor to the Company (whether direct or
               ----------                                                  
indirect and whether by purchase, lease, merger, consolidation, liquidation or
otherwise) to all or substantially all of the Company's business and/or assets
shall assume the obligations under this Agreement and agree expressly to perform
the obligations under this Agreement in the same manner and to the same extent
as the Company would be required to perform such obligations in the absence of a
succession.  The terms of this Agreement and all of the Employee's rights
hereunder shall inure to the benefit of, and be enforceable by, the Employee's
personal or legal representatives, executors, administrators, successors, heirs,
distributees, devisees and legatees.

          8.   Notice.  Notices and all other communications contemplated by
               ------                                                       
this Agreement shall be in writing and shall be deemed to have been duly given
when personally delivered or when mailed by U.S. registered or certified mail,
return receipt requested and postage prepaid.  Mailed notices to the Employee
shall be addressed to the Employee at the 

                                      -5-
<PAGE>
 
home address which the Employee most recently communicated to the Company in
writing. In the case of the Company, mailed notices shall be addressed to its
corporate headquarters, and all notices shall be directed to the attention of
its Secretary.

          9.   Miscellaneous Provisions.
               ------------------------ 
                
               (a) No Duty to Mitigate.  The Employee shall not be required to
                   -------------------                                        
mitigate the amount of any payment contemplated by this Agreement (whether by
seeking new employment or in any other manner), nor, except as otherwise
provided in this Agreement, shall any such payment be reduced by any earnings
that the Employee may receive from any other source.

               (b) Waiver.  No provision of this Agreement shall be modified,
                   ------    
waived or discharged unless the modification, waiver or discharge is agreed to
in writing and signed by the Employee and by an authorized officer of the
Company (other than the Employee). No waiver by either party of any breach of,
or of compliance with, any condition or provision of this Agreement by the other
party shall be considered a waiver of any other condition or provision or of the
same condition or provision at another time.

               (c) Whole Agreement.  No agreements, representations or
                   ---------------                            
understandings (whether oral or written and whether express or implied) which
are not expressly set forth in this Agreement have been made or entered into by
either party with respect to the subject matter hereof. This Agreement
supersedes any agreement of the same title and concerning similar subject matter
dated prior to the date of this Agreement, and by execution of this Agreement
both parties agree that any such predecessor agreement shall be deemed null and
void.
               (d) Choice of Law.  The validity, interpretation, construction
                   -------------  
and performance of this Agreement shall be governed by the laws of the State of
California without reference to conflict of laws provisions.

               (e) Severability.  If any term or provision of this Agreement or
                   ------------     
the application thereof to any circumstance shall, in any jurisdiction and to
any extent, be invalid or unenforceable, such term or provision shall be
ineffective as to such jurisdiction to the extent of such invalidity or
unenforceability without invalidating or rendering unenforceable the remaining
terms and provisions of this Agreement or the application of such terms and
provisions to circumstances other than those as to which it is held invalid or
unenforceable, and a suitable and equitable term or provision shall be
substituted therefor to carry out, insofar as may be valid and enforceable, the
intent and purpose of the invalid or unenforceable term or provision.

               (f) Arbitration.  Any dispute or controversy arising under or in
                   -----------                                                 
connection with this Agreement may be settled at the option of either party by
binding arbitration in the County of Contra Costa, California, in accordance
with the rules of the American Arbitration Association then in effect.  Judgment
may be entered on the arbitrator's  award in any court having jurisdiction.
Punitive damages shall not be awarded.

                                      -6-
<PAGE>
 
               (g) Legal Fees and Expenses.  The parties shall each bear their
                   -----------------------    
own expenses, legal fees and other fees incurred in connection with this
Agreement.

               (h) No Assignment of Benefits.  The rights of any person to
                   -------------------------   
payments or benefits under this Agreement shall not be made subject to option or
assignment, either by voluntary or involuntary assignment or by operation of
law, including (without limitation) bankruptcy, garnishment, attachment or other
creditor's process, and any action in violation of this subsection (h) shall be
void.
               (i) Employment Taxes.  All payments made pursuant to this
                   ----------------      
Agreement will be subject to withholding of applicable income and employment
taxes.

               (j) Assignment by Company.  The Company may assign its rights
                   ---------------------  
under this Agreement to an affiliate, and an affiliate may assign its rights
under this Agreement to another affiliate of the Company or to the Company;
provided, however, that no assignment shall be made if the net worth of the
assignee is less than the net worth of the Company at the time of assignment. In
the case of any such assignment, the term "Company" when used in a section of
this Agreement shall mean the corporation that actually employs the Employee.

               (k) Counterparts.  This Agreement may be executed in
                   ------------    
counterparts, each of which shall be deemed an original, but all of which
together will constitute one and the same instrument.

     IN WITNESS WHEREOF, each of the parties has executed this Agreement, in the
case of the Company by its duly authorized officer, as of the day and year first
above written.


KERAVISION, INC.                              THOMAS M. LOARIE


By:   /s/ Mark Fischer-Colbrie                /s/  Thomas M. Loarie

Title:    Vice President, Finance

                                      -7-


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