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                                                                      EXHIBIT 10



                      SETTLEMENT AND DISSOLUTION AGREEMENT

         This Settlement and Dissolution Agreement is made and entered into this
4th day of June, 1998 (the "Effective Date"), between and among Summit
Technology, Inc., a corporation organized under the laws of the Commonwealth of
Massachusetts ("Summit"), Summit Partner, Inc., a corporation organized under
the laws of the State of Delaware ("SPI"), VISX, Incorporated, a corporation
organized under the laws of the State of Delaware ("VISX"), VISX Partner, Inc.,
a corporation organized under the laws of the State of Delaware ("VPI") and
Pillar Point Partners, a Delaware general partnership whose general partners are
SPI and VPI ("Pillar Point").

                              W I T N E S S E T H:

         WHEREAS, Summit and VISX caused Pillar Point to be formed in 1992 to
resolve certain patent disputes and, in connection therewith, entered into a
Formation Agreement dated June 3, 1992 ("Formation Agreement") and caused their
affiliates SPI and VPI to enter into a Partnership Agreement of even date
("Partnership Agreement"); and

         WHEREAS, in accordance with the provisions of the Formation Agreement
and the Partnership Agreement, Summit and VISX, through SPI and VPI, each caused
to be contributed to Pillar Point the exclusive licensing rights in and to
certain of their patents containing claims covering methods and apparatus for
performing ultraviolet laser corneal surgery in the United States and agreed
automatically to contribute to Pillar Point similar rights in any subsequently
issued patents under any U.S. patent application having a filing or priority
date in whole or in part occurring on or before June 3, 1993, as well as rights
in certain Precluding Patents (as defined in the Formation Agreement); and

         WHEREAS, Summit and VISX each entered into License Back Agreements with
Pillar Point ("License Back Agreements"), pursuant to which Pillar Point granted
to each a non-exclusive license to the Pillar Point patents (the License Back,
Formation and Partnership Agreements, together with all amendments thereto and
the collateral documentation executed and delivered in connection therewith, are
hereinafter collectively referred to as the "Pillar Point Agreements"); and

         WHEREAS, on June 17, 1997, Summit and VISX entered into a settlement
agreement (the "Azema Settlement Agreement"), pursuant to which the parties
resolved certain patent disputes, released various claims, cross licensed
certain of each other's foreign patents, covenanted not to sue each other for
patent infringement, and caused the exclusive licensing rights to Summit's
United States Azema Patents (as defined in the Azema Settlement Agreement) to be
contributed to Pillar Point; and

         WHEREAS, Pillar Point, Summit and VISX are involved in numerous
disputes between and among themselves and with third parties relating to Pillar
Point; and

         WHEREAS, Summit and VISX desire to reach a final and complete
settlement of all claims, disputes and lawsuits between them, dissolve Pillar
Point, cross license patents and

exchange general releases, all in accordance with the terms and conditions of
this Settlement and Dissolution Agreement;

         NOW, THEREFORE, in consideration of the payments, releases, licenses,
covenants and undertakings hereinafter set forth, Pillar Point, Summit and VISX
agree as follows:

                               A G R E E M E N T:

      1.    AFFILIATES. For purposes of this Settlement and Dissolution
Agreement, the term "Affiliate" means (a) any corporation, entity or person that
now or in the future owns or acquires at least 85% of the shares entitled to
vote of Summit or VISX or that otherwise acquires Summit or VISX by merger,
consolidation, or acquisition of substantially all of the assets of Summit or
VISX or (b) any corporation, entity or person with respect to which, now or in
the future, Summit or VISX owns or acquires at least 85% of the shares entitled
to vote of such corporation, entity or person or that is otherwise acquired by
Summit or VISX by merger, consolidation or acquisition of substantially all of
the assets of such corporation, person or entity. Under no circumstances shall a
cooperative venture (as defined at Section 11, below) be deemed to qualify a
third party as an Affiliate of VISX or Summit, absent compliance with the
specific provisions of this Section 1. Hereinafter, references to Summit and
VISX in this Settlement and Dissolution Agreement (including, for example,
references to cross licenses granted between Summit and VISX) shall be deemed to
include their respective Affiliates.



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      2.    PATENTS. (a) For purposes of this Settlement and Dissolution
Agreement, the term "Summit Patents" means all U.S. and foreign patents issued
to Summit or in which Summit in the future acquires an ownership interest or the
right to license others to practice the art embodied in the patent, AND which
relate to a method or apparatus for laser ablation of corneal tissue. (b) For
purposes of this Settlement and Dissolution Agreement, the term "VISX Patents"
means all U.S. and foreign patents issued to VISX or in which VISX in the future
acquires an ownership interest or the right to license others to practice the
art embodied in the patent, AND which relate to a method or apparatus for laser
ablation of corneal tissue. Without limitation, the Summit Patents and the VISX
Patents include all of the Patents included or includable in Pillar Point by
virtue of the Pillar Point Agreements.

      3.    PAYMENT. In consideration for the settlement of litigation and
releases described in Sections 8, 12 and 14, below, within one (1) business day
of the Effective Date, VISX shall make a single lump sum cash payment to Summit
in the amount of Thirty-Five Million Dollars ($35,000,000), in good, immediately
available funds, wired to the following account: BankBoston, Account #551-06959,
ABA #011000390, 100 Federal Street, Boston, Massachusetts 02110 (or such other
account as Summit may direct). In the event VISX fails to timely make the
payment described in this Section 3, Summit shall have the option of either (i)
terminating this Agreement and treating it as null and void or (ii) treating the
Agreement as effective and suing VISX in the United States District Court for
the District of Massachusetts or any other court of competent jurisdiction for
breach of contract and/or to specifically enforce VISX's payment and other
obligations hereunder. In the event of such suit, VISX (i) consents to the
jurisdiction and venue selected by Summit and (ii) shall be liable for all of
Summit's costs of suit, including attorneys' fees.

      4.    ROYALTY-FREE LICENSE TO VISX. Pillar Point hereby grants to VISX an
irrevocable, perpetual, non-exclusive, non-transferable, fully paid up license
under the Summit Patents to make, have made, use, offer to sell, sell, lease and
otherwise dispose of products that come within the claims of the Summit Patents,
whether directly or indirectly through distributors or other resellers, and to
perform and sublicense others to perform procedures using those products or
which are covered by method claims of the Summit Patents, in the United States.

      5.    ROYALTY-FREE LICENSE TO SUMMIT. Pillar Point hereby grants to Summit
an irrevocable, perpetual, non-exclusive, non-transferable, fully paid up
license under the VISX Patents, to make, have made, use, offer to sell, sell,
lease and otherwise dispose of products that come within the claims of the VISX
Patents, whether directly or indirectly through distributors or other resellers,
and to perform and sublicense others to perform procedures using those products
or which are covered by method claims of the VISX Patents, in the United States.

      6.    DISSOLUTION OF PILLAR POINT. Effective immediately following the
grant of the licenses described in Sections 4 and 5, above ("Payment Date"),
Pillar Point is hereby dissolved, and, subject only to the terms of this
Agreement, the Pillar Point Agreements are terminated and all rights to license,
prosecute, defend and otherwise deal in and with the VISX Patents shall revert
back to VISX or its designee (subject to, among other terms of this Agreement,
the terms of Section 5, above), and all rights to license, prosecute, defend and
otherwise deal in and with the Summit Patents shall revert back to Summit or its
designee (subject to, among other terms of this Agreement, the terms of Section
4, above). From and after the Payment Date, neither Summit nor VISX shall have
any further payment or other obligation to Pillar Point in respect of equipment
royalties, procedure royalties, or otherwise.

      7.    WINDING UP AND TERMINATION OF PILLAR POINT. Notwithstanding the
provisions of Section 6, above, Pillar Point shall remain in existence after the
Payment Date for the sole purpose of winding up its affairs, defending or
settling remaining litigation in which it is or becomes a defendant and/or
completing the defense of any such litigation. Except as specifically set forth
below, liability for costs and expenses incurred by Pillar Point prior to
dissolution, and for ongoing expenses of Pillar Point incurred in connection
with the winding up activities described above, shall be allocated 60% to VISX
and 40% to Summit. Rights to remaining Pillar Point assets, including cash,
claims against third parties (such as patent infringement) and receivables held
by Pillar Point which accrued prior to the Payment Date or which otherwise
remain in Pillar Point after winding up, shall be allocated 60% to VISX and 40%
to Summit. Until the Payment Date, the License Back Agreements will remain in
force and the parties will remain liable for royalties to Pillar Point accruing
prior thereto, provided that each party may calculate royalties using the same
assumptions and contract interpretations as were used in the immediately prior
month.

      8.    [REDACTED]

      9.    VISX CROSS LICENSE. Summit hereby grants to VISX an irrevocable,
perpetual, worldwide, non-exclusive, non-transferable, fully paid up license
under the Summit Patents, and any divisions, reissues, re-examinations,
continuations, continuations in part, renewals, extensions and additions
thereto, to make, have made, use, offer to sell, sell, import, lease and
otherwise dispose of products that come within the claims of the Summit Patents,
whether directly or indirectly through distributors or other resellers, and to



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perform and sublicense others to perform procedures using those products or
which are covered by method claims of the Summit Patents. As used herein, the
term "non-transferable" is not intended to alter or diminish the parties'
intention that their present or future Affiliates shall enjoy the benefits of
the cross licenses described in this Agreement without necessity of further
action (subject to Section 11 below).

      10.   SUMMIT CROSS LICENSE. VISX hereby grants to Summit an irrevocable,
perpetual, worldwide, non-exclusive, non-transferable, fully paid up license
under the VISX Patents and any divisions, reissues, re-examinations,
continuations, continuations in part, renewals, extensions and additions
thereto, to make, have made, use, offer to sell, sell, import, lease and
otherwise dispose of products that come within the claims of the VISX Patents,
whether directly or indirectly through distributors or other resellers, and to
perform and sublicense others to perform procedures using those products or
which are covered by method claims of the VISX Patents. As used herein, the term
"non-transferable" is not intended to alter or diminish the parties' intention
that their present or future Affiliates shall enjoy the benefits of the cross
licenses described in this Agreement without necessity of further action
(subject to Section 11 below).

      11.   [REDACTED]

      12.   DISMISSAL OF LITIGATION. Within five (5) days of the Effective Date,
Summit, VISX and Pillar Point shall cause all of the Summit/VISX Litigation (as
hereinafter defined) to be dismissed with prejudice, with each party to bear its
own costs and attorneys' fees. As used herein, "Summit/VISX Litigation" means
VISX Partner, Inc. v. Summit Partner, Inc., Santa Clara County Superior Court,
Case No. CV 772057; VISX, Incorporated v. Pillar Point Partners, et al., Santa
Clara County Superior Court, Case No. 770042; and VISX Partner, Inc., on behalf
Pillar Point Partners, United States District Court, District Of Massachusetts,
Case No. 96-11739-PBS. The term "Summit/VISX Litigation" includes all
counterclaims, cross-claims and the like asserted in the foregoing actions.

      13.   RELEASE BY VISX. Except for Claims (as defined in this Paragraph 13)
for breach of this Settlement and Dissolution Agreement, VPI, VISX, and Pillar
Point, on behalf of themselves and their respective officers, directors,
employees, representatives, predecessors, successors, agents, assigns and
attorneys (together, the "VISX Releasors"), do hereby forever release and
discharge SPI, Summit, and their respective officers, directors, employees,
representatives, predecessors, successors, agents, assigns and attorneys
(together, the "Summit Releasees"), from any and all actions, causes of action,
suits, debts, sums of money, accounts, reckonings, bonds, bills, contracts,
controversies, agreements, promises, damages, judgments, awards, executions,
claims and demands whatsoever, including without limitation costs and attorneys'
fees, in law, admiralty or equity, or as a result of any arbitration, whether
known or unknown to any of the VISX Releasors (collectively, "Claims"), which
the VISX Releasors, or any of them, ever had, now have or hereafter can, shall,
or may have, whether in their own right or by assignment, transfer or grant from
any other person, upon or by reason of any matter, cause or thing whatsoever,
from the beginning of the world to the Effective Date, including, but not
limited to, any Claims relating directly or indirectly to Pillar Point and the
Pillar Point Agreements (including royalties and payments alleged to be due and
owing thereunder), unfair trade practices, false or misleading advertising
claims or otherwise.

      14.   RELEASE BY SUMMIT. Except for (i) the possible claims relating to
the Trokel Patents described in Section 8(a)(vi), above, below and in the
Tolling Agreement, and (ii) Claims (as defined in this Paragraph 14) for breach
of this Settlement and Dissolution Agreement, Pillar Point, SPI, Summit, and
Summit's Affiliates, on behalf of themselves and their respective officers,
directors, employees, representatives, predecessors, successors, agents, assigns
and attorneys (together, the "Summit Releasors"), effective on the Payment Date
do hereby forever release and discharge VPI, VISX and VISX's Affiliates, and
their respective officers, directors, employees, representatives, predecessors,
successors, agents, assigns and attorneys (together, the "VISX Releasees") from
any and all actions, causes of action, suits, debts, sums of money, accounts,
reckonings, bonds, bills, contracts, controversies, agreements, promises,
damages, judgments, awards, executions, claims and demands whatsoever, including
without limitation costs and attorneys' fees, in law, admiralty or equity, or as
a result of any arbitration, whether known or unknown to any of the Summit
Releasors (collectively, "Claims"), which the Summit Releasors, or any of them,
ever had, now have or hereafter can, shall, or may have, whether in their own
right or by assignment, transfer or grant from any other person, upon or by
reason of any matter, cause or thing whatsoever, from the beginning of the world
to the Effective Date, including, but not limited to, any Claims relating
directly or indirectly to Pillar Point and the Pillar Point Agreements
(including royalties and payments alleged to be due and owing thereunder or
Claims of wrongful dissolution thereof).

      15.   COVENANTS NOT TO SUE. (a) Summit hereby covenants never to sue or
threaten to sue VISX or VISX's distributors, customers, or users and never to
make any claim whatsoever against VISX or VISX's distributors, customers or
users anywhere in the world, for any alleged infringement of any patent
(whenever issued) which relates to a method or apparatus for laser ablation of
corneal tissue, or for any alleged infringement of any patent owned by Summit as
of the Effective Date and which relates to refractive correction of the eye, on
the basis of the manufacture, use, offer to sell, sale, sublicense to customers
or users, lease or other disposition of products that come within the claims of
such patents; (b) VISX hereby covenants never to sue or threaten to sue Summit
or Summit's distributors, 



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customers, or users and never to make any claim whatsoever against Summit or
Summit's distributors or customers, anywhere in the world, for any alleged
infringement of any patent (whenever issued) which relates to a method or
apparatus for laser ablation of corneal tissue, or for any alleged infringement
of any patent owned by VISX as of the Effective Date and which relates to
refractive correction of the eye, on the basis of the manufacture, use, offer to
sell, sale, sublicense to customers or users, lease or other disposition of
products that come within the claims of such patents.

      16.   ADMISSIBILITY. Nothing in this Settlement and Dissolution Agreement
shall be construed as an admission by any party of any liability of any kind to
the other party. This Settlement and Dissolution Agreement shall not be
admissible as evidence against any party hereto or its Affiliates in any
proceeding other than in a proceeding to enforce an obligation of a party
hereunder or as proof of the dissolution of Pillar Point.

      17.   NOTICES. Any notice given pursuant to this Settlement and
Dissolution Agreement shall be in writing and, except as otherwise expressly
provided herein, shall be deemed to have been duly delivered if delivered in
person or by certified or registered or overnight express mail, postage and
mailing expense prepaid, or by facsimile transmission with hard copy to follow
by regular mail, and, if given or rendered to Summit or its Affiliates addressed
to:

                           Summit Technology, Inc.
                           21 Hickory Drive
                           Waltham, Massachusetts 02154
                           Attention: Chief Executive Officer

or if given or rendered to VISX or its Affiliates addressed to:

                           VISX, Incorporated
                           3400 Central Expressway
                           Santa Clara, California  95051
                           Attention: Chief Executive Officer

Either party may specify a different address by notifying the other in writing
of such different address.

      18.   SEVERABILITY. If any provision of this Settlement and Dissolution
Agreement, or the application of such provision to any person or circumstance,
shall be held to be invalid or unenforceable, the remainder of this Settlement
and Dissolution Agreement, or the application of such provision to such persons
or circumstances other than those to which it is held invalid or unenforceable,
shall not be affected thereby, provided that such invalid or unenforceable
provisions shall be replaced by valid and enforceable provisions which will
achieve as far as possible the economic and business intentions of the parties
to this Settlement and Dissolution Agreement.

      19.   SUMMIT ACKNOWLEDGMENT. Summit hereby warrants and represents that
(a) it has read and understood the terms of this Settlement and Dissolution
Agreement; (b) it has the full right and authority (i) to enter into this
Settlement and Dissolution Agreement, (ii) to grant the licenses, releases,
covenants and undertakings recited herein on its own behalf and on behalf of
each Summit Affiliate, and (iii) to enter into the agreements received herein on
its own behalf and on behalf of each Summit Affiliate; and (c) there are no
outstanding agreements, assignments, or encumbrances inconsistent with the
provisions set forth in this Settlement and Dissolution Agreement.

      20.   VISX ACKNOWLEDGMENT. VISX hereby warrants and represents that (a) it
has read and understood the terms of this Settlement and Dissolution Agreement;
(b) it has the full right and authority (i) to enter into this Settlement and
Dissolution Agreement, (ii) to grant the licenses, releases, covenants and
undertakings recited herein on its own behalf and on behalf of each VISX
Affiliate, and (iii) to enter into the agreements recited herein on its own
behalf and on behalf of each VISX Affiliate; and (c) there are no outstanding
agreements, assignments, or encumbrances inconsistent with the provisions set
forth in this Settlement and Dissolution Agreement.

      21.   INTEGRATION. Except as otherwise specifically set forth herein, this
Settlement and Dissolution Agreement, together with its Exhibits, represents the
entire agreement and understanding between and among the parties hereto with
respect to the subject matter hereof and supersedes any and all prior or
contemporaneous discussions, agreements and understandings relating thereto.
Specifically, except as otherwise expressly provided herein, each of the
following agreements is expressly terminated and superseded as of the Effective
Date by operation of this Settlement and Dissolution Agreement.



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            -     Formation Agreement dated June 3, 1992 among VISX, Summit,
                  VPI, and SPI

            -     General Partnership Agreement, dated June 3, 1992, between SPI
                  and VPI

            -     License-back to Summit Agreement dated June 3, 1992

            -     License-back to VISX Agreement dated June 3, 1992

            -     Contribution Agreement between SPI and Pillar Point dated June
                  3, 1992

            -     Contribution Agreement between VPI and Pillar Point dated June
                  3, 1992

            -     The following sections of the Azema Settlement Agreement: 4
                  (Definition of Affiliate); 9(b) (License to VISX); 10(b)
                  (License to Summit); 11(a) and 12(a) (Covenants Not to Sue);
                  and 24 (Integration).

            -     Tolling Agreement dated February 12, 1998, between Summit and
                  VISX

      It is the intent of the parties that the Joint Defense Agreement among
them relating to the Third Party Litigation shall survive execution of this
Settlement Agreement. This Settlement and Dissolution Agreement may not be
varied or modified other than by a writing executed on behalf of each of the
parties hereto. With the exception of transfers of rights to present or future
Affiliates (which occurs without necessity of further action), neither VISX nor
Summit shall assign, transfer, or delegate any of its rights, duties and
obligations under this Settlement and Dissolution Agreement without the express
written consent of the other party, which consent shall not be unreasonably
withheld.

      22.   STRICT PERFORMANCE. The failure by any party to insist upon the
strict performance of any covenant, duty, agreement or condition of this
Settlement and Dissolution Agreement or to exercise any right or remedy
consequent upon a breach thereof shall not constitute waiver of any such breach
or any other covenant, duty, agreement or condition.

      23.   INDEMNIFICATION. Each of Summit and VISX (for purposes of this
Paragraph 23, each a "Licensee") shall indemnify, defend and hold harmless the
other party and its successors and assigns (for purposes of this Paragraph 23,
each a "Licensor") from and against any loss, damage, cost or expense of
whatsoever kind or nature (including reasonable attorneys' fees and professional
expenses) incurred by the Licensor by reason of any product liability claim
arising out of the manufacture, use, sale, lease, license or other disposition
of products manufactured or marketed by Licensee or any Licensee Affiliate or
any distributor of Licensee or any Licensee Affiliate and licensed hereunder.
The foregoing indemnification and agreement to defend and hold harmless shall
include, without limitation, any cost or expense incurred or to be incurred by
the Licensor or any Licensor Affiliate by reason of its having been or being
made a party or being threatened to be made a party to any threatened, pending
or completed action, suit or proceeding, whether civil, criminal, administrative
or investigative in connection with any actual or alleged act or omission in
connection with any such manufacture, use, sale, lease, license or other
disposition of products manufactured or assembled by Licensee or any Licensee
Affiliate or performance of any procedures using those products. The foregoing
indemnification and agreement to defend and hold harmless shall not extend to
any acts or omissions by or on behalf of the Licensor or its Affiliates in bad
faith or as a result of negligence. A party claiming indemnification shall not
be entitled to indemnification with respect to any action to which it consented
in writing or any claim as to which it did not give written notice to the party
from which indemnification is sought within ninety (90) days after having
received notice of such claim. IN NO EVENT SHALL EITHER PARTY BE LIABLE TO THE
OTHER FOR ANY INCIDENTAL, PUNITIVE, SPECIAL OR CONSEQUENTIAL DAMAGES. In the
event any claim for indemnification arises from a claim of a third party, the
party from whom indemnification is sought shall have the right to defend against
such third party claim and, in such event, the party seeking indemnification
shall cooperate with all reasonable requests in the defense thereof at the
expense of the party from whom indemnification is sought.

      24.   NO AGENCY. Nothing in this Settlement Agreement shall be deemed to

appoint or authorize any party to act as an agent of the other party or to
assume or incur any liability or obligation in the name or on behalf of the
other party.

      25.   LABELS. (a) VISX shall affix to each product covered by one or more
of the Summit Patents that is sold, licensed, leased or otherwise disposed of
after the Effective Date a label reasonably requested by Summit listing the
applicable Summit Patent(s). The purpose of the label is to provide notice of
the Summit Patents to other parties to establish or support a claim by Summit
against any such 




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other party of damages due to infringement. Summit and VISX agree that any such
label will not be introduced into evidence, produced, relied upon, or used in
any way in any proceeding between Summit and VISX, except in a proceeding
related to enforcement of the terms of this Settlement and Dissolution
Agreement; (b) Summit shall affix to each product covered by one or more of the
VISX Patents that is sold, licensed, leased or otherwise disposed of after the
Effective Date a label reasonably requested by VISX listing the applicable VISX
Patent(s). The purpose of the label is to provide notice of the VISX Patents to
other parties to establish or support a claim by VISX against any such other
party of damages due to infringement. Summit and VISX agree that any such label
will not be introduced into evidence, produced, relied upon, or used in any way
in any proceeding between Summit and VISX, except in a proceeding related to
enforcement of the terms of this Settlement and Dissolution Agreement.

      26.   GOVERNING LAW. This Settlement and Dissolution Agreement shall be
governed by the laws of the State of Delaware. The terms of this Settlement and
Dissolution Agreement may be enforced in any court of competent jurisdiction.
Both parties hereby acknowledge and submit to the jurisdiction of the Federal
District Court for the District of Delaware to hear and resolve any dispute over
terms of the Settlement and Dissolution Agreement, to protect and enforce the
parties' rights hereunder, to rectify the contract if necessary, and to order
specific performance, injunction or similar equitable relief.

      27.   COUNTERPARTS. This Settlement and Dissolution Agreement may be
executed in separate counterparts, each of which shall be considered an original
but all of which shall constitute one agreement.

      28.   PUBLIC STATEMENTS. Summit and VISX agree that neither of them shall
make any public statements about this Settlement and Dissolution Agreement or
its terms, except as may be set forth in the joint press release referred to
below or as required by applicable securities laws. VISX and Summit shall be
permitted to disclose the terms of this Settlement and Dissolution Agreement to
the Federal Trade Commission, and to any other person or entity if ordered to do
so by a court of competent jurisdiction, and VISX and Summit shall be permitted
to issue a joint press release, after the Effective Date, announcing the fact
that they have settled outstanding disputes and agreed to dissolve Pillar Point
Partners and the general terms of the Agreement.





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      WHEREFORE, the parties hereto, having been duly authorized to do so, have
caused this Settlement and Dissolution Agreement to be executed as of the date
first above written.




SUMMIT TECHNOLOGY, INC.                        VISX, INCORPORATED


By: /s/ Robert J. Palmisano                    By: /s/ Elizabeth Davila 
    ----------------------------------             ----------------------------
    Robert J. Palmisano                            Elizabeth Davila
    Chief Executive Officer                        Executive Vice President,
                                                   Chief Operating Officer


SUMMIT PARTNER, INC.                           VISX PARTNER, INC.

By: /s/ Robert J. Palmisano                    By: /s/ Elizabeth Davila 
    ----------------------------------             ----------------------------
    Robert J. Palmisano                            Elizabeth Davila
    Title: Chief Executive Officer                 Vice President

By: /s/ James Lightman                         By: /s/ Katrina Church
    ----------------------------------             ----------------------------
    James Lightman                                 Katrina Church
    Secretary                                      Secretary


PILLAR POINT PARTNERS                          PILLAR POINT PARTNERS

By: SUMMIT PARTNER, INC.                       By: VISX PARTNER, INC.
ITS GENERAL PARTNER                            ITS GENERAL PARTNER

By: /s/ Robert J. Palmisano                    By: /s/ Elizabeth Davila 
    ----------------------------------             ----------------------------
    Robert J. Palmisano                            Elizabeth Davila
    Chief Executive Officer                        Vice President



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