Underwriting Agreement - VISX Inc., Dillon Read & Co. Inc. and PaineWebber Inc.


VISX, INCORPORATED
 
                                  COMMON STOCK
 
                                ($.01 PAR VALUE)
 
                             UNDERWRITING AGREEMENT
 
            , 1995

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                             UNDERWRITING AGREEMENT
 
                                                                          , 1995
 
Dillon, Read & Co. Inc.
535 Madison Avenue
New York, New York 10022
 
PaineWebber Incorporated
1285 Avenue of the Americas
New York, New York 10009
 
  as Managing Underwriters
 
Dear Sirs:
 
     VISX Incorporated, a Delaware corporation (the "Company"), proposes to
issue and sell to the underwriters named in Schedule A (the "Underwriters")
2,500,000 shares (the "Firm Shares") of Common Stock, par value $.01 per share
(the "Common Stock"), of the Company. In addition, solely for the purpose of
covering overallotments, the Company proposes to issue and sell, at the
Underwriters' option, up to 375,000 additional shares of the Common Stock (the
"Additional Shares"). The Additional Shares and the Firm Shares are collectively
referred to as the "Shares". The Shares are described in the Prospectus which is
referred to below.
 
     The Company has filed, in accordance with the provisions of the Securities
Act of 1933, as amended, and the rules and regulations thereunder (collectively,
the "Act"), with the Securities and Exchange Commission (the "Commission") a
registration statement on Form S-3, including a prospectus, relating to the
Shares, which incorporates by reference certain documents that the Company has
filed in accordance with the provisions of the Securities Exchange Act of 1934,
as amended, and the rules and regulations thereunder (collectively, the
"Exchange Act"). The Company has furnished to you, for use by the Underwriters
and by dealers, copies of one or more preliminary prospectuses and all documents
incorporated by reference therein (collectively, the "Preliminary Prospectus")
relating to the Shares. Except where the context otherwise requires, the
registration statement as in effect at the time of execution of this Agreement
or, if the registration statement is not yet effective, as amended when it
becomes effective, including all documents filed as a part thereof or
incorporated by reference therein, and including any information contained in a
prospectus subsequently filed with the Commission pursuant to Rule 424(b) under
the Act and deemed to be part of the registration statement at the time of
effectiveness pursuant to Rule 430A under the Act, is herein called the
"Registration Statement", and the prospectus, including all documents
incorporated therein by reference, in the form filed by the Company with the
Commission pursuant to Rule 424(b) under the Act or, if no such filing is
required, in the form of final prospectus included in the Registration Statement
at the time it became effective, is herein called the "Prospectus".
 
     The Company and the Underwriters agree as follows:
 
     1. Sale and Purchase.  On the basis of the representations and warranties
and the other terms and conditions herein set forth, the Company agrees to sell
to the respective Underwriters and each of the Underwriters, severally and not
jointly, agrees to purchase from the Company, the number of Firm Shares set
forth opposite the name of such Underwriter on Schedule A, at a purchase price
of $          per Share. You may release the Firm Shares for public sale
promptly after this Agreement becomes effective. You may from time to time
increase or decrease the public offering price after the initial public offering
to such extent as you may determine.
 
     In addition, on the basis of the representations and warranties and the
other terms and conditions herein set forth, the Company hereby grants to the
several Underwriters an option to purchase, and the Underwriters shall have the
right to purchase, severally and not jointly, from the Company all or a portion
of the Additional

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Shares as may be necessary to cover overallotments made in connection with the
offering of the Firm Shares, at the same purchase price per share to be paid by
the several Underwriters to the Company for the Firm Shares. This option may be
exercised at any time or from time to time on or before the thirtieth day
following the date hereof, by written notice to the Company. Such notice shall
set forth the aggregate number of Additional Shares as to which the option is
being exercised, and the date and time when the Additional Shares are to be
delivered (such date and time being herein referred to as an "additional time of
purchase"); provided, however, that no additional time of purchase shall occur
earlier than the time of purchase (as defined below) nor earlier than the second
business day* after the date on which the option shall have been exercised nor
later than the eighth business day after the date on which the option shall have
been exercised. The number of Additional Shares to be sold to each Underwriter
at an additional time of purchase shall be the number which bears the same
proportion to the aggregate number of Additional Shares being purchased at such
additional time of purchase as the number of Firm Shares set forth opposite the
name of such Underwriter on Schedule A bears to the total number of Firm Shares
(subject, in each case, to such adjustment as you may determine to eliminate
fractional shares).
 
     2. Payment and Delivery.  Payment of the purchase price for the Firm Shares
shall be made to the Company by certified or official bank check, in New York
Clearing House funds, at the office of Dillon, Read & Co. Inc. in New York City,
against delivery of the certificates for the Firm Shares to you for the
respective accounts of the Underwriters. Such payment and delivery shall be made
at 9:30 A.M., New York City time, on               , 1995 (unless another time
shall be agreed to by you and the Company or unless postponed in accordance with
the provisions of Section 8). The time at which such payment and delivery are
actually made is called the "time of purchase". Certificates for the Firm Shares
shall be delivered to you in definitive form in such names and in such
denominations as you shall specify on the second business day preceding the time
of purchase. For the purpose of expediting the checking of the certificates for
the Firm Shares by you, the Company agrees to make such certificates available
to you for such purpose at least one full business day preceding the time of
purchase.
 
     Payment of the purchase price for the Additional Shares shall be made to
the Company at the additional time of purchase in the same manner and at the
same office as the payment for the Firm Shares. Certificates for the Additional
Shares shall be delivered to you in definitive form in such names and in such
denominations as you shall specify on the second business day preceding the
additional time of purchase. For the purpose of expediting the checking of the
certificates for the Additional Shares by you, the Company agrees to make such
certificates available to you for such purpose at least one full business day
preceding the additional time of purchase.
 
     3. Representations and Warranties of the Company.  The Company represents
and warrants to each of the Underwriters that:
 
          (a) Each Preliminary Prospectus filed as part of the Registration
     Statement as originally filed or as part of any amendment thereto, or filed
     pursuant to Rule 424 under the Act, complied when so filed in all material
     respects with the Act; when the Registration Statement becomes or became
     effective and at all times subsequent thereto up to the time of purchase
     and the additional time of purchase, the Registration Statement and the
     Prospectus, and any supplements or amendments thereto, complied and will
     comply in all material respects with the provisions of the Act; and the
     Registration Statement at all such times did not and will not contain an
     untrue statement of a material fact or omit to state a material fact
     required to be stated therein or necessary to make the statements therein
     not misleading, and the Prospectus at all such times did not and will not
     contain an untrue statement of a material fact or omit to state a material
     fact required to be stated therein or necessary to make the statements
     therein, in light of the circumstances under which they were made, not
     misleading; provided, however, that the Company makes no representation or
     warranty with respect to any statement contained in the Registration
     Statement or the Prospectus in reliance upon and in conformity with
     information concerning the Underwriters and furnished in writing by or on
     behalf of any Underwriter through you to the Company expressly for use in
 
- ---------------
 
* As used herein, "business day" shall mean a day on which the New York Stock
  Exchange is open for trading.
 
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     the Registration Statement or the Prospectus and set forth in the section
     of the Registration Statement and the Prospectus entitled "Underwriting";
     the documents incorporated by reference in the Prospectus, at the time they
     were filed with the Commission, complied in all material respects with the
     requirements of the Exchange Act, and do not contain an untrue statement of
     a material fact or omit to state a material fact required to be stated
     therein or necessary to make the statements therein, in light of the
     circumstances under which they were made, not misleading.
 
          (b) As of the date of this Agreement, the Company has an authorized
     capitalization as set forth under the column entitled "June 30, 1995
     Actual" in the section of the Registration Statement and the Prospectus
     entitled "Capitalization" and, as of the time of purchase, the
     capitalization of the Company will be as set forth under the column
     entitled "June 30, 1995 As Adjusted" in the section of the Registration
     Statement and the Prospectus entitled "Capitalization"; all of the issued
     and outstanding shares of capital stock of the Company have been duly
     authorized and validly issued and are fully paid and nonassessable; the
     Company has been duly organized and is validly existing as a corporation in
     good standing under the laws of the State of Delaware with full power and
     authority to (i) own its properties and conduct its business as described
     in the Registration Statement and the Prospectus and (ii) execute and
     deliver this Agreement and to issue, sell and deliver the Shares as herein
     contemplated.
 
          (c) The Company does not own any interest in any corporation, joint
     venture or partnership except VISX Partner, Inc., a Delaware corporation
     (the "Subsidiary"). VISX Partner, Inc. does not own any interest in any
     corporation, joint venture or partnership, except that it is a general
     partner of Pillar Point Partners, a Delaware general partnership (the
     "Partnership"). All of the issued and outstanding shares of capital stock
     of the Subsidiary are owned directly by the Company; all of such shares
     have been duly authorized and validly issued and are fully paid and
     nonassessable and, except as described in the Prospectus, are owned free
     and clear of any pledge, lien, encumbrance, security interest or other
     claim; there are no outstanding rights, subscriptions, warrants, calls,
     preemptive rights, options or other agreements of any kind with respect to
     the capital stock of the Subsidiary.
 
          (d) The Subsidiary owns the general partnership interests (the
     "Partnership Interests") of the Partnership contemplated by the General
     Partnership Agreement dated as of June 3, 1992 between the Subsidiary and
     Summit Partner, Inc.; the Partnership Interests are owned free and clear of
     any pledge, lien, encumbrance, security interest or other claim; there are
     no outstanding rights, subscriptions, warrants, calls, preemptive rights,
     options or other agreements of any kind with respect to the partnership
     interests of the Partnership.
 
          (e) The Subsidiary has been duly incorporated and is validly existing
     as a corporation in good standing under the laws of its jurisdiction of
     incorporation, with full corporate power and authority to own its
     properties and to conduct its businesses.
 
          (f) The Partnership has been duly organized and is validly existing as
     a general partnership under the laws of Delaware, with full power and
     authority to own its properties and to conduct its business.
 
          (g) Each of the Company and the Subsidiary is duly qualified or
     licensed by and is in good standing in each jurisdiction in which it owns
     or leases property or conducts its business and in each other jurisdiction
     in which the failure, individually or in the aggregate, to be so qualified
     or licensed could have a material adverse effect on the properties, assets,
     operations, business, business prospects or condition (financial or other)
     of the Company and the Subsidiary taken as a whole; each of the Company and
     the Subsidiary is in compliance in all material respects with the laws,
     orders, rules, regulations and directives issued or administered by each
     such jurisdiction; the Partnership is in compliance in all material
     respects with the laws, orders, rules, regulations and directives issued or
     administered by each jurisdiction in which it owns or leases property or
     conducts its business.
 
          (h) Neither the Company nor the Subsidiary is in breach of, or in
     default under (nor has any event occurred which with notice, lapse of time
     or both would constitute a breach of, or default under), its charter or
     bylaws, or in the performance or observance of any obligation, agreement,
     covenant or condition contained in any license, indenture, lease, mortgage,
     deed of trust, bank loan or credit
 
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     agreement, material supply agreement or other agreement or instrument to
     which the Company or the Subsidiary is a party or by which either of them
     may be bound or affected. The execution, delivery and performance of this
     Agreement, the issuance of the Shares and the consummation of the
     transactions contemplated hereby will not conflict with, or result in any
     breach of or constitute a default under (nor constitute any event which
     with notice, lapse of time or both would constitute a breach of, or default
     under), the charter or bylaws of the Company or the Subsidiary or under any
     provision of any license, indenture, lease, mortgage, deed of trust, bank
     loan or credit agreement, material supply agreement or other agreement or
     instrument to which the Company or the Subsidiary is a party or by which
     either of them or their properties may be bound or affected, or under any
     federal, state, local or foreign law, regulation or rule or any decree,
     judgment or order applicable to the Company or the Subsidiary.
 
          (i) The Partnership is not in breach of, or in default under (nor has
     any event occurred which with notice, lapse of time or both would
     constitute a breach of, or default under), in the performance or observance
     of any obligation, agreement, covenant or condition contained in any
     license, indenture, lease, mortgage, deed of trust, bank loan or credit
     agreement, material supply agreement or other agreement or instrument to
     which the Partnership is a party or by which it may be bound or affected.
 
          (j) The Firm Shares and the Additional Shares, when issued and
     delivered to and paid for by the Underwriters as contemplated hereby, will
     be duly authorized and validly issued and fully paid and nonassessable,
     free and clear of any pledge, lien, encumbrance, security interest,
     preemptive right or other claim.
 
          (k) This Agreement has been duly authorized, executed and delivered by
     the Company.
 
          (l) The capital stock of the Company, including the Shares, conforms
     in all material respects to the description thereof contained in the
     Registration Statement and the Prospectus; and the certificates for the
     Shares are in due and proper form and the holders of the Shares after
     making payment therefor will not be subject to personal liability under the
     General Corporation Law of Delaware by reason of being such holders.
 
          (m) No approval, authorization, consent or order of or filing with any
     federal, state, local or foreign governmental or regulatory commission,
     board, body, authority or agency is required in connection with the
     issuance and sale of the Shares as contemplated hereby, other than
     registration of the Shares under the Act, clearance of the offering of the
     Shares with the National Association of Securities Dealers, Inc. (the
     "NASD") and any necessary qualification under the securities or blue sky
     laws of the various jurisdictions in which the Shares are being offered by
     the Underwriters.
 
          (n) No person has the right, contractual or otherwise, to cause the
     Company to issue to it, or (except for such rights as have been satisfied
     or waived) register pursuant to the Act, any securities of the Company in
     consequence of the issue and sale of the Shares to the Underwriters
     hereunder, nor does any person have preemptive rights, rights of first
     refusal or other rights to purchase any of the Shares.
 
          (o) Arthur Andersen LLP, whose reports on the consolidated financial
     statements of the Company and the Subsidiary are included or incorporated
     by reference in the Registration Statement and the Prospectus, are
     independent public accountants with respect to the Company as required by
     the Act and the applicable published rules and regulations thereunder.
 
          (p) Each of the Company, the Subsidiary and the Partnership has all
     necessary licenses, authorizations, consents and approvals and has made all
     necessary filings required under any federal, state, local or foreign law,
     regulation or rule, and has obtained all necessary authorizations,
     consents, licenses and approvals from other persons, in order to conduct
     its business; neither the Company, the Subsidiary nor the Partnership is in
     violation of, or in default under, any such license, authorization, consent
     or approval or any federal, state, local or foreign law, regulation or rule
     or any decree, order or judgment applicable to the Company, the Subsidiary
     or the Partnership the result of which could have a material adverse effect
     on the properties, assets, operations, business, business prospects or
     condition (financial or other) of the Company and the Subsidiary taken as a
     whole.
 
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          (q) All legal or governmental proceedings, contracts or documents of a
     character required to be described in the Registration Statement or the
     Prospectus or to be filed as an exhibit to the Registration Statement have
     been so described or filed as required.
 
          (r) Except as set forth in the Registration Statement and the
     Prospectus, there is no action, suit or proceeding pending or threatened
     against the Company, the Subsidiary or the Partnership or any of their
     properties, at law or in equity, or before or by any federal, state, local
     or foreign governmental or regulatory commission, board, body, authority or
     agency that could result in a judgment, decree or order having a material
     adverse effect on the properties, assets, operations, business, business
     prospects or condition (financial or other) of the Company and the
     Subsidiary taken as a whole.
 
          (s) The audited and unaudited financial statements included in the
     Registration Statement and the Prospectus present fairly the consolidated
     financial condition of the Company and the Subsidiary as of the dates
     indicated and the consolidated results of operations and cash flows of the
     Company and the Subsidiary for the periods specified; such financial
     statements have been prepared in conformity with generally accepted
     accounting principles applied on a consistent basis during the periods
     involved.
 
          (t) Subsequent to the respective dates as of which information is
     given in the Registration Statement and the Prospectus, and except as may
     be otherwise stated in the Registration Statement or the Prospectus, there
     has not been: (A) any material adverse change in the properties, assets,
     operations, business, business prospects or condition (financial or other),
     present or prospective, of the Company and the Subsidiary taken as a whole;
     (B) any transaction, that is material to the Company and the Subsidiary
     taken as a whole, contemplated or entered into by the Company, the
     Subsidiary or the Partnership; or (C) any obligation, contingent or
     otherwise, directly or indirectly incurred by the Company, the Subsidiary
     or the Partnership that is material to the Company and the Subsidiary taken
     as a whole.
 
          (u) The Company has obtained the agreement of the stockholders listed
     on Schedule B not to sell, contract to sell, grant any option to sell,
     transfer or otherwise dispose of, directly or indirectly, any shares of
     Common Stock, or securities convertible into or exchangeable for Common
     Stock or warrants or other rights to purchase Common Stock for a period of
     90 days from the date of the Prospectus.
 
          (v) The business, operations and facilities of the Company and the
     Subsidiary have been and are being conducted in compliance in all material
     respects with all applicable laws, ordinances, rules, regulations,
     licenses, permits, approvals, plans, authorizations or requirements
     relating to occupational safety and health, or pollution, or protection of
     health or the environment, or reclamation (including without limitation
     those relating to emissions, discharges, releases or threatened releases of
     pollutants, contaminants or hazardous or toxic substances, materials or
     wastes into ambient air, surface water, groundwater or land, or relating to
     the manufacture, processing, distribution, use, treatment, storage,
     disposal, transport or handling of chemical substances, pollutants,
     contaminants or hazardous or toxic substances, materials or wastes, whether
     solid, gaseous or liquid in nature) or otherwise relating to remediating
     real property in which the Company or the Subsidiary has any interest,
     whether owned or leased, of any governmental department, commission, board,
     bureau, agency or instrumentality of the United States, any state or
     political subdivision thereof or any foreign jurisdiction and all
     applicable judicial or administrative agency or regulatory decrees, awards,
     judgments and orders relating thereto; and neither the Company nor the
     Subsidiary has received any notice from a governmental instrumentality or
     any third party alleging any violation thereof or liability thereunder
     (including without limitation liability for costs of investigating or
     remediating sites containing hazardous substances or damages to natural
     resources).
 
          (w) Neither the Company nor the Subsidiary, nor any employee of the
     Company or the Subsidiary, has made any payment of funds of the Company or
     the Subsidiary prohibited by law, and no funds of the Company or the
     Subsidiary have been set aside to be used for any payment prohibited by
     law.
 
          (x) The Company, the Subsidiary and the Partnership have filed all
     federal or state income or franchise tax returns required to be filed and
     have paid all taxes shown thereon as due, and there is no material tax
     deficiency which has been or might be asserted against the Company, the
     Subsidiary or the Partnership; all material tax liabilities are adequately
     provided for on the books of the Company, the Subsidiary and the
     Partnership.
 
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          (y) The Company has not incurred any liability for any finder's fees
     or similar payments in connection with the transactions herein
     contemplated.
 
          (z) The Company, the Subsidiary and the Partnership have good title to
     all properties and assets owned or leased by them, in each case free and
     clear of all liens, security interests, pledges, charges, encumbrances,
     mortgages and defects (except such as are described or referred to in the
     Prospectus and the financial statements and the notes thereto contained
     therein or such as do not interfere with the use made and proposed to be
     made of such property by the Company, the Subsidiary and the Partnership).
 
          (aa) Neither the Company nor the Subsidiary is an "investment company"
     within the meaning of the Investment Company Act of 1940, as amended, or is
     subject to regulation under such Act.
 
     4. Certain Covenants of the Company.  The Company hereby agrees:
 
          (a) to furnish such information as may be required and otherwise to
     cooperate in qualifying the Shares for offering and sale under the
     securities or blue sky laws of such states as you may designate and to
     maintain such qualifications in effect as long as required for the
     distribution of the Shares, provided that the Company shall not be required
     to qualify as a foreign corporation or to consent to the service of process
     under the laws of any such state (except service of process with respect to
     the offering and sale of the Shares); promptly to advise you of the receipt
     by the Company of any notification with respect to the suspension of the
     qualification of the Shares for sale in any jurisdiction or the initiation
     or threatening of any proceeding for such purpose; and to use its best
     efforts to obtain the withdrawal of any order of suspension at the earliest
     practicable moment;
 
          (b) to make available to you in New York City, as soon as practicable
     after the Registration Statement becomes effective, and thereafter from
     time to time to furnish to the Underwriters, as many copies of the
     Prospectus (or of the Prospectus as amended or supplemented if the Company
     shall have made any amendment or supplement thereto after the effective
     date of the Registration Statement) as the Underwriters may request for the
     purposes contemplated by the Act;
 
          (c) to advise you promptly and if requested by you to confirm such
     advice in writing, (i) when the Registration Statement has become effective
     and when any post-effective amendment thereto becomes effective and (ii)
     when the Prospectus is filed with the Commission pursuant to Rule 424(b)
     under the Act, if required under the Act (which the Company agrees to file
     in a timely manner under such Rule);
 
          (d) to advise you promptly, confirming such advice in writing, of any
     request by the Commission for amendments or supplements to the Registration
     Statement or the Prospectus or for additional information with respect
     thereto, or of notice of institution of proceedings for or the entry of a
     stop order suspending the effectiveness of the Registration Statement and,
     if the Commission should enter a stop order suspending the effectiveness of
     the Registration Statement, to use its best efforts to obtain the lifting
     or removal of such order as soon as possible; to advise you promptly of any
     proposal to amend or supplement the Registration Statement or the
     Prospectus, including by filing any document that would be incorporated
     therein by reference, and to file no such amendment or supplement to which
     you shall object in writing;
 
          (e) to furnish to you and, upon request to each of the other
     Underwriters, for a period of five years from the date of this Agreement
     (i) copies of all reports or other communications that the Company shall
     send to its stockholders or from time to time shall publish or publicly
     disseminate and (ii) copies of all annual, quarterly and current reports
     filed with the Commission on Forms 10-K, 10-Q and 8-K, or such other
     similar form as may be designated by the Commission, and any other document
     filed by the Company pursuant to Section 12, 13, 14 or 15(d) of the
     Exchange Act;
 
          (f) to advise the Underwriters promptly of the happening of any event
     known to the Company within the time during which a prospectus relating to
     the Shares is required to be delivered under the Act that, in the
     reasonable judgment of the Company, would require the making of any change
     in the Prospectus then being used, or in the information incorporated
     therein by reference, so that the Prospectus, as then supplemented, would
     not include an untrue statement of a material fact or omit to
 
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     state a material fact necessary to make the statements therein, in the
     light of the circumstances under which they are made, not misleading and,
     during such time, promptly to prepare and furnish, at the Company's
     expense, to the Underwriters such amendments or supplements to such
     Prospectus as may be necessary to reflect any such change in such
     quantities as requested by the Underwriters, and to furnish to you a copy
     of such proposed amendment or supplement before filing any such amendment
     or supplement with the Commission;
 
          (g) to make generally available to its security holders, and to
     deliver to you, an earnings statement of the Company (which need not be
     audited and which will satisfy the provisions of Section 11(a) of the Act
     including, at the option of the Company, Rule 158) covering a period of 12
     months beginning after the effective date of the Registration Statement but
     ending not later than 15 months after the date of the Registration
     Statement, as soon as is reasonably practicable after the termination of
     such 12-month period;
 
          (h) to furnish to you three signed copies of the Registration
     Statement, as initially filed with the Commission, and of all amendments
     thereto (including all exhibits thereto and documents incorporated by
     reference therein) and sufficient conformed copies of the foregoing (other
     than exhibits) for distribution of a copy to each of the other
     Underwriters;
 
          (i) to furnish to you as early as practicable prior to the time of
     purchase and the additional time of purchase, as the case may be, but not
     later than two business days prior thereto, a copy of the latest available
     unaudited interim consolidated financial statements, if any, of the Company
     and the Subsidiary that have been read by the Company's independent
     certified public accountants as stated in their letter to be furnished
     pursuant to Section 6(b);
 
          (j) to apply the net proceeds from the sale of the Shares in the
     manner set forth under the caption "Use of Proceeds" in the Registration
     Statement and the Prospectus;
 
          (k) to use its best efforts to cause the Shares to be included in the
     Nasdaq National Market;
 
          (l) whether or not the transactions contemplated in this Agreement are
     consummated or this Agreement otherwise becomes effective or is terminated,
     to pay all expenses, fees and taxes (other than (x) any transfer taxes and
     (y) fees and disbursements of your counsel except as set forth under
     Section 5 and clauses (iii) and (iv) below) in connection with (i) the
     preparation and filing of the Registration Statement, each Preliminary
     Prospectus, the Prospectus and any amendment or supplement thereto, and the
     printing and furnishing of copies of each thereof to you and to dealers
     (including costs of mailing and shipment), (ii) the issuance, sale and
     delivery of the Shares, (iii) the word processing or printing of this
     Agreement and any dealer agreements, and the reproduction or printing and
     furnishing of copies of each thereof to you and to dealers (including costs
     of mailing and shipment), (iv) the qualification of the Shares for offering
     and sale under state laws as aforesaid (including legal fees and filing
     fees and other disbursements of your counsel) and the printing and
     furnishing of copies of any blue sky surveys to you and to dealers, (v) any
     listing of the Shares on any securities exchange or qualification of the
     Shares for inclusion in the Nasdaq National Market and any registration
     thereof under the Exchange Act, (vi) any filing for review of the public
     offering of the Shares by the NASD and (viii) the performance of the
     Company's other obligations hereunder;
 
          (m) not to sell, contract to sell, grant any option to sell, transfer
     or otherwise dispose of, directly or indirectly, any shares of Common Stock
     or securities convertible into or exchangeable for Common Stock or warrants
     or other rights to purchase Common Stock or permit the registration under
     the Act of any shares of Common Stock, except for the registration of the
     Shares and the sales to you pursuant to this Agreement for a period
     commencing on the date hereof and continuing for    days after the date of
     the Prospectus, without the prior written consent of Dillon, Read & Co.
     Inc., except for the issuance of shares of Common Stock (i) upon exercise
     of options granted prior to the date hereof under the Company's stock
     option plans to the extent such options become exercisable in accordance
     with their terms; and (ii) pursuant to the Company's Employee Stock
     Purchase Plan described in Note 5 to the Company's consolidated financial
     statements included in the Registration Statement; and
 
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          (n) to refrain from investing the proceeds from the sale of the Shares
     in a manner to cause the Company or the Subsidiary to become an "investment
     company" within the meaning of the Investment Company Act of 1940, as
     amended.
 
     5. Reimbursement of Underwriters' Expenses.  If the Shares are not
delivered for any reason other than as provided in the second paragraph of
Section 7, the Company will reimburse the Underwriters for all of their
out-of-pocket expenses, including the fees and disbursements of their counsel.
 
     6. Conditions of Underwriters' Obligations.  The several obligations of the
Underwriters hereunder are subject to the accuracy of the representations and
warranties on the part of the Company on the date hereof and at the time of
purchase (and the several obligations of the Underwriters at the additional time
of purchase are subject to the accuracy of the representations and warranties on
the part of the Company on the date hereof and at the time of purchase and at
the additional time of purchase, as the case may be), the performance by the
Company of its obligations hereunder and to the following conditions:
 
          (a) The Company shall furnish to you at the time of purchase and at
     the additional time of purchase, as the case may be, an opinion of Wilson,
     Sonsini, Goodrich & Rosati, counsel for the Company, addressed to the
     Underwriters, and dated the time of purchase or the additional time of
     purchase, as the case may be, with reproduced copies for each of the other
     Underwriters and in form satisfactory to Gibson, Dunn & Crutcher, counsel
     for the Underwriters, stating that:
 
             (i) the Company has been duly incorporated and is validly existing
        as a corporation in good standing under the laws of the State of
        Delaware, with full corporate power and authority (A) to own its
        properties and conduct its business as described in the Registration
        Statement and the Prospectus and (B) to execute and deliver this
        Agreement and to issue, sell and deliver the Shares as herein
        contemplated;
 
             (ii) to the best of such counsel's knowledge, the Company does not
        own any interest in any corporation, joint venture or partnership except
        the Subsidiary and the Partnership; the Subsidiary has been duly
        incorporated and is validly existing as a corporation in good standing
        under the laws of the state in which such Subsidiary is incorporated,
        with full corporate power and authority to own its properties and to
        conduct its business as described in the Registration Statement and the
        Prospectus;
 
             (iii) The Subsidiary owns the Partnership Interests; the
        Partnership Interests are owned free and clear of any pledge, lien,
        encumbrance, security interest or other claim; there are no outstanding
        rights, subscriptions, warrants, calls, preemptive rights, options or
        other agreements of any kind with respect to the partnership interests
        of the Partnership.
 
             (iv) each of the Company and the Subsidiary is duly qualified or
        licensed to do business by and is in good standing as a foreign
        corporation in each jurisdiction in which it conducts business or owns
        property and in which the failure, individually or in the aggregate, to
        be so licensed or qualified could have a material adverse effect on the
        properties, assets, operations, business, business prospects or
        condition (financial or other) of the Company and the Subsidiary taken
        as a whole;
 
             (v) the Partnership has been duly organized and is validly existing
        as a general partnership in good standing under the laws of Delaware,
        with full power and authority to own its properties and to conduct its
        business.
 
             (vi) all of the issued and outstanding shares of capital stock of
        the Subsidiary have been duly authorized and validly issued and are
        fully paid and nonassessable and, except as set forth in the Prospectus,
        are owned, directly or indirectly, by the Company free and clear of any
        pledge, lien, encumbrance, security interest, preemptive right or other
        claim, and there are no rights, warrants, options or other agreements to
        acquire or instruments convertible into or exchangeable for any shares
        of capital stock or other equity interest of the Subsidiary, except as
        set forth in the Prospectus;
 
             (vii) this Agreement has been duly authorized, executed and
        delivered by the Company;
 
                                        8

   10
 
             (viii) (a) the Shares, when issued and delivered to and paid for by
        the Underwriters, will be duly authorized, validly issued, fully paid
        and nonassessable, and will be free of any pledge, lien, encumbrance,
        claim or preemptive right; and (b) the certificates for the Shares are
        in due and proper form and the holders of the Shares will not be subject
        to personal liability by reason of being such holders;
 
             (ix) (a) the Company has an authorized capitalization as set forth
        under the heading "Capitalization" in the Registration Statement and the
        Prospectus, and (b) the outstanding shares of capital stock of the
        Company have been duly authorized and validly issued and are fully paid,
        nonassessable and free of statutory and contractual preemptive rights;
 
             (x) the capital stock of the Company, including the Shares,
        conforms in all material respects to the description thereof contained
        in the Registration Statement and the Prospectus;
 
             (xi) the Registration Statement and the Prospectus (except as to
        the financial statements and schedules contained or incorporated by
        reference therein as to which such counsel need express no opinion)
        comply as to form in all material respects with the requirements of the
        Act;
 
             (xi) the Registration Statement has become effective under the Act
        and, to the best of such counsel's knowledge, no stop order proceedings
        with respect thereto are pending or threatened under the Act;
 
             (xiii) no approval, authorization, consent or order of or filing
        with any federal, state, local or foreign governmental or regulatory
        commission, board, body, authority or agency is required in connection
        with the issuance or sale of the Shares as contemplated hereby other
        than registration of the Shares under the Act (except such counsel need
        express no opinion as to any necessary qualification under the state
        securities or blue sky laws of the various jurisdictions in which the
        Shares are being offered by the Underwriters);
 
             (xiv) the execution, delivery and performance of this Agreement by
        the Company and the consummation by the Company of the transactions
        contemplated hereby do not and will not conflict with, or result in any
        breach of, or constitute a default under (nor constitute any event which
        with notice, lapse of time or both would constitute a breach of or
        default under), the charter or bylaws of the Company or the Subsidiary,
        or any provision of any license, indenture, lease, mortgage, deed of
        trust, bank loan or credit agreement or other agreement or instrument to
        which the Company or the Subsidiary is a party or by which the Company
        or the Subsidiary or their properties are bound or affected, or under
        any federal, state, local or foreign law, regulation or rule or any
        decree, judgment or order applicable to the Company or the Subsidiary;
 
             (xv) to the best of such counsel's knowledge, neither the Company,
        the Subsidiary nor the Partnership is in breach of or in default under
        (nor has any event occurred which with notice, lapse of time or both
        would constitute a breach of or default under) any license, indenture,
        lease, mortgage, deed of trust, bank loan or credit agreement or any
        other agreement or instrument to which the Company, the Subsidiary or
        the Partnership is a party or by which the Company, the Subsidiary or
        the Partnership or their properties are bound or affected or under any
        law, regulation or rule or any decree, judgment or order applicable to
        the Company, the Subsidiary or the Partnership, except for such matters
        as could not, individually or in the aggregate, have a material adverse
        effect on the properties, assets, operations, business, business
        prospects or condition (financial or other) of the Company and the
        Subsidiary taken as a whole;
 
             (xvi) all contracts or documents of a character required to be
        described in the Registration Statement or the Prospectus or to be filed
        as an exhibit to the Registration Statement have been so described or
        filed;
 
             (xvii) except as described in the Registration Statement and the
        Prospectus, there are no actions, suits or proceedings of which such
        counsel has knowledge pending or threatened against the Company, the
        Subsidiary or the Partnership, or any of their respective properties, at
        law or in equity,
 
                                        9

   11
 
        or before or by any federal, state, local or foreign governmental or
        regulatory commission, board, body, authority or agency that
        individually or in the aggregate could result in a judgment, decree or
        order having a material adverse effect on the properties, assets,
        operations, business, business prospects or condition (financial or
        other) of the Company and the Subsidiary taken as a whole;
 
             (xviii) the documents incorporated by reference in the Registration
        Statement and Prospectus, when they were filed (or, if an amendment with
        respect to any such document was filed, when such amendment was filed),
        complied as to form in all material respects with the Exchange Act
        (except as to the financial statements and schedules and other financial
        and statistical data contained or incorporated by reference therein, as
        to which such counsel need express no opinion);
 
             (xix) to the best of such counsel's knowledge, each person who has
        the right, contractual or otherwise, to request the Company to register
        pursuant to the Act securities of the Company upon the issue and sale of
        the Shares to the Underwriters hereunder or who has preemptive rights,
        rights of first refusal or other rights to purchase any of the Shares,
        except to the extent included in the Registration Statement, either
        waived such rights or was excluded from including any such shares in
        this offering, or from any preemptive rights, rights of first refusal or
        other purchase rights, in accordance with the terms thereof;
 
             (xx) the statements in the Registration Statement and the
        Prospectus under the captions ["Risk Factors -- Lack of FDA Approval;
        Government Regulation,"] "Risk Factors -- Dependence on Third-Party
        Sales and Marketing," ["Risk Factors -- Reliance on Patents and
        Proprietary Technology; Risk of Infringement and Litigation,"] "Risk
        Factors -- Risks Relating to Pillar Point Partners," "Risk
        Factors -- Potential Claims for Personal Injury," "Business -- Pillar
        Point and Other Licensing Agreements," "Business -- Marketing, Sales and
        Distribution," ["Business -- Government Regulation,"]
        ["Business -- Patents and Proprietary Rights,"] "Business -- Insurance
        and Indemnification," "Business -- Facilities" and "Business -- Legal
        Proceedings," insofar as they are descriptions of laws, regulations and
        rules, of legal and governmental proceedings or of contracts,
        agreements, leases and other legal documents, or refer to statements of
        law or legal conclusions, have been reviewed by such counsel and are
        accurate in all material respects [order and section names to be
        conformed to revised draft];
 
             (xxi) neither the Company nor the Subsidiary is an "investment
        company" or a person "controlled" by an "investment company" within the
        meaning of the Investment Company Act of 1940, as amended;
 
             (xxii) the sales of securities by the Company described in Item 15
        of the Registration Statement were exempt from the registration
        requirements of the Act; and
 
             (xxiii) nothing has come to the attention of such counsel that
        causes them to believe that the Registration Statement or any amendment
        thereto at the time such Registration Statement or amendment became
        effective contained an untrue statement of a material fact or omitted to
        state a material fact required to be stated therein or necessary to make
        the statements therein not misleading, or that the Prospectus or any
        supplement thereto at the date of such Prospectus or such supplement,
        and at all times up to and including the time of purchase contained an
        untrue statement of a material fact or omitted to state a material fact
        required to be stated therein or necessary to make the statements
        therein, in light of the circumstances under which they were made, not
        misleading (it being understood that such counsel need express no
        opinion with respect to the financial statements and schedules included
        in the Registration Statement or Prospectus).
 
          (b) You shall have received from Arthur Andersen LLP letters dated,
     respectively, the date of this Agreement and the time of purchase and
     additional time of purchase, as the case may be, and addressed to the
     Underwriters (with reproduced copies for each of the Underwriters) in form
     and substance satisfactory to the Managing Underwriters.
 
          (c) You shall have received at the time of purchase and at the
     additional time of purchase, as the case may be, opinions from Gibson, Dunn
     & Crutcher in form and substance satisfactory to you.
 
                                       10

   12
 
          (d) No amendment or supplement to the Registration Statement or the
     Prospectus, including documents deemed to be incorporated by reference
     therein, shall be filed prior to the time the Registration Statement
     becomes effective to which you shall have objected in writing.
 
          (e) The Registration Statement shall become effective at or before
     5:00 P.M., New York City time, on the date of this Agreement and, if Rule
     430A under the Act is used, the Prospectus shall have been filed with the
     Commission pursuant to Rule 424(b) under the Act at or before 5:00 P.M.,
     New York City time, on the second full business day after the date of this
     Agreement; provided, however, that the Company and you and any group of
     Underwriters, including you, who have agreed hereunder to purchase in the
     aggregate at least 50% of the Firm Shares from time to time may agree in
     writing or by telephone, confirmed in writing, on a later date.
 
          (f) Prior to the time of purchase or the additional time of purchase,
     as the case may be: (i) no stop order with respect to the effectiveness of
     the Registration Statement shall have been issued under the Act or
     proceedings initiated under Section 8(d) or 8(e) of the Act; (ii) the
     Registration Statement and all amendments thereto, or modifications
     thereof, if any, shall not contain an untrue statement of a material fact
     or omit to state a material fact required to be stated therein or necessary
     to make the statements therein not misleading; and (iii) the Prospectus and
     all amendments or supplements thereto, or modifications thereof, if any,
     shall not contain an untrue statement of a material fact or omit to state a
     material fact required to be stated therein or necessary to make the
     statements therein, in light of the circumstances under which they were
     made, not misleading.
 
          (g) Between the time of execution of this Agreement and the time of
     purchase or the additional time of purchase, as the case may be, there has
     not been: (i) any material and adverse change, present or prospective, in
     the properties, assets, operations, business, business prospects or
     condition (financial or other) of the Company and the Subsidiary taken as a
     whole, other than as described in the Registration Statement and the
     Prospectus; (ii) any transaction that is material to the Company and the
     Subsidiary taken as a whole contemplated or entered into by the Company or
     the Subsidiary, other than as described in the Registration Statement and
     the Prospectus; or (iii) any obligation, contingent or otherwise, directly
     or indirectly, incurred by the Company or the Subsidiary that is material
     to the Company and the Subsidiary taken as a whole, other than as described
     in the Registration Statement and the Prospectus.
 
          (h) The Company, at the time of purchase or additional time of
     purchase, as the case may be, will deliver to you a certificate of two of
     its executive officers to the effect that the representations and
     warranties of the Company as set forth in this Agreement are true and
     correct as of each such date and the conditions set forth in Section 6(f)
     and Section 6(g) have been met.
 
          (i) You shall have received a signed letter, dated the date of this
     Agreement, from each of the stockholders listed in Schedule B to the effect
     that such persons shall not sell, contract to sell, grant any option to
     sell, transfer or otherwise dispose of, directly or indirectly, any shares
     of Common Stock or securities convertible into or exchangeable for Common
     Stock or warrants or other rights to purchase Common Stock for a period of
     90 days from the date of the Prospectus without the prior written consent
     of Dillon, Read & Co. Inc.
 
          (j) The Company shall have furnished to you such other documents and
     certificates as to the accuracy and completeness of any statement in the
     Registration Statement or the Prospectus as of the time of purchase and the
     additional time of purchase, as the case may be, as you reasonably may
     request.
 
          (k) The Company shall have performed such of its obligations under
     this Agreement as are to be performed by the terms hereof at or before the
     time of purchase and at or before the additional time of purchase, as the
     case may be.
 
          (l) The Shares shall have been approved for quotation through the
     Nasdaq National Market.
 
     7. Effective Date of Agreement; Termination.  This Agreement shall become
effective (i) if Rule 430A under the Act is not used, when you shall have
received notification of the effectiveness of the Registration
 
                                       11

   13
 
Statement, or (ii) if Rule 430A under the Act is used, when the parties hereto
have executed and delivered this Agreement.
 
     The obligations of the several Underwriters hereunder shall be subject to
termination in the absolute discretion of you or any group of Underwriters
(which may include you) which has agreed to purchase in the aggregate at least
50% of the Firm Shares if, at any time prior to the time of purchase or, with
respect to the purchase of any Additional Shares, the additional time of
purchase, as the case may be, trading in securities on the New York Stock
Exchange shall have been suspended or minimum prices shall have been established
on the New York Stock Exchange, or if a banking moratorium shall have been
declared either by the United States or New York State authorities, or if the
United States shall have declared war in accordance with its constitutional
processes or there shall have occurred any material outbreak or escalation of
hostilities or other national or international calamity or crisis of such
magnitude in its effect on, or any material adverse change in, any financial
market which, in each case, in your judgment, or in the judgment of such group
of Underwriters, makes it impracticable to market the Shares.
 
     If you or any group of Underwriters elect to terminate this Agreement as
provided in this Section 7, the Company and each other Underwriter shall be
notified promptly by letter or telegram.
 
     If the sale to the Underwriters of the Shares, as contemplated by this
Agreement, is not carried out by the Underwriters for any reason permitted under
this Agreement or if such sale is not carried out because the Company shall be
unable to comply with any of the terms of this Agreement, the Company shall not
be under any obligation or liability under this Agreement (except to the extent
provided in Sections 4(l), 5 and 9), and the Underwriters shall be under no
obligation or liability to the Company under this Agreement (except to the
extent provided in Section 9).
 
     8. Increase in Underwriters' Commitments.  If any Underwriter shall default
in its obligation to take up and pay for the Firm Shares to be purchased by it
hereunder and if the number of Firm Shares which all Underwriters so defaulting
shall have agreed but failed to take up and pay for does not exceed 10% of the
total number of Firm Shares, the non-defaulting Underwriters shall take up and
pay for (in addition to the aggregate principal amount of Firm Shares they are
obligated to purchase pursuant to Section 1) the number of Firm Shares agreed to
be purchased by all such defaulting Underwriters as hereinafter provided. Such
Shares shall be taken up and paid for by such non-defaulting Underwriter or
Underwriters in such amount or amounts as you may designate with the consent of
each Underwriter so designated or, in the event no such designation is made,
such Shares shall be taken up and paid for by all non-defaulting Underwriters
pro rata in proportion to the aggregate number of Firm Shares set opposite the
names of such non-defaulting Underwriters in Schedule A.
 
     Without relieving any defaulting Underwriter from its obligations
hereunder, the Company agrees with the non-defaulting Underwriters that they
will not sell any Firm Shares hereunder unless all of the Firm Shares are
purchased by the Underwriters (or by substituted Underwriters selected by you
with the approval of the Company or selected by the Company with your approval).
 
     If a new Underwriter or Underwriters are substituted by the Underwriters or
by the Company for a defaulting Underwriter or Underwriters in accordance with
the foregoing provision, the Company or you shall have the right to postpone the
time of purchase for a period not exceeding five business days in order that any
necessary change in the Registration Statement and the Prospectus and other
documents may be effected.
 
     The term Underwriter as used in this Agreement shall refer to and include
any Underwriter substituted under this Section 8 with like effect as if such
substituted Underwriter had originally been named in Schedule A.
 
     9. Indemnity by the Company and the Underwriters.
 
     (a) The Company agrees to indemnify, defend and hold harmless each
Underwriter, each person that controls any Underwriter within the meaning of
Section 15 of the Act or Section 20 of the Exchange Act, and each Underwriter's
agents, employees, officers and directors and the agents, employees, officers
and directors of any such controlling person (collectively, the "Underwriter
indemnified parties") from and against any and
 
                                       12

   14
 
all losses, claims, damages, judgments, liabilities and expenses (including the
fees and expenses of counsel and other expenses in connection with
investigating, defending or settling any such action or claim) which, jointly or
severally, any Underwriter indemnified party may incur as they are incurred (and
regardless of whether such Underwriter indemnified party is a party to the
litigation, if any) arising out of or based upon any untrue statement or alleged
untrue statement of a material fact contained in the registration statement
relating to the Shares or the Prospectus or any Preliminary Prospectus, or
arising out of or based upon any omission or alleged omission to state therein a
material fact required to be stated therein or necessary to make the statements
therein not misleading, except insofar as such losses, claims, damages,
judgments, liabilities or expenses arise out of, or are based upon, any such
untrue statement or omission or alleged untrue statement or omission based upon
and in conformity with information with respect to any Underwriter furnished in
writing by any Underwriter through you to the Company expressly for use therein
with reference to such Underwriter. This indemnity agreement will be in addition
to any liability the Company otherwise may have.
 
     (b) If any action or proceeding (including any governmental or regulatory
investigation or proceeding) shall be brought or asserted against any
Underwriter indemnified party, with respect to which indemnity may be sought
against the Company pursuant to this Section 8, such Underwriter indemnified
party shall promptly notify the Company in writing, and the Company shall assume
the defense thereof, including the employment of counsel reasonably satisfactory
to the Underwriter indemnified party and payment of all fees and expenses;
provided that the omission so to notify the Company shall not relieve it from
any liability that it may have to any Underwriter indemnified party. An
Underwriter indemnified party shall have the right to employ separate counsel in
any such action or proceeding and to assume the defense thereof, but the fees
and expenses of such counsel shall be at the expense of such Underwriter
indemnified party unless (i) the employment of such counsel has been authorized
in writing by the Company, (ii) the Company has failed promptly to assume the
defense and employ counsel satisfactory to the Underwriter indemnified party or
(iii) the named parties to any such action or proceeding (including any
impleaded parties) include both the Underwriter indemnified party and the
Company and such Underwriter indemnified party shall have reasonably concluded
that there may be one or more legal defenses available to it that are different
from or additional to those available to the Company (in which case the Company
shall not have the right to assume the defense of such action on behalf of such
Underwriter indemnified party), in any of which events such fees and expenses
shall be borne by the Company and reimbursed as they are incurred. It is
understood, however, that the Company shall not, in connection with any one such
action or separate but substantially similar or related actions in the same
jurisdiction arising out of the same general allegations or circumstances, be
liable for the fees and expenses of more than one separate firm of attorneys (in
addition to any local counsel) at any time for all such Underwriter indemnified
parties, which firm shall be designated in writing by Dillon, Read & Co. Inc.,
and that all such fees and expenses shall be reimbursed as they are incurred.
The Company shall not be liable for any settlement of any such action effected
without the written consent of the Company (which consent shall not be
unreasonably withheld or delayed), but if settled with the written consent of
the Company, or if there is a final judgment with respect thereto, the Company
agrees to indemnify and hold harmless each Underwriter indemnified party from
and against any loss or liability by reason of such settlement or judgment.
 
     (c) Each Underwriter severally agrees to indemnify and hold harmless the
Company, its directors, its officers who sign the Registration Statement, and
any person that controls the Company within the meaning of Section 15 of the Act
or Section 20 of the Exchange Act (collectively, the "Company indemnified
parties") to the same extent as the foregoing indemnity from the Company to the
Underwriter indemnified parties, but only with respect to information concerning
such Underwriter furnished in writing by or on behalf of such Underwriter
through you to the Company expressly for use with respect to such Underwriter in
the Registration Statement, any Preliminary Prospectus or the Prospectus. In
case any action shall be brought against any Company indemnified party based on
the Registration Statement, any Preliminary Prospectus or the Prospectus and in
respect of which indemnity may be sought against any Underwriter pursuant to
this Section 8(c), such Underwriter shall have the rights and duties given to
the Company by Section 8(b) (except that if the Company shall have assumed the
defense thereof such Underwriter shall not be required to do so, but may employ
separate counsel therein and participate in the defense thereof, provided that
the fees and expenses of such separate counsel shall be at the expense of such
Underwriter), and the Company
 
                                       13

   15
 
indemnified parties shall have the rights and duties given to the Underwriter
indemnified parties by Section 8(b).
 
     (d) If the indemnification provided for in this Section 8 is unavailable to
or insufficient to hold harmless any Underwriter indemnified party or any
Company indemnified party, then the party required to indemnify such indemnified
party under this Section 8, in lieu of indemnifying such indemnified party,
shall contribute to the amount paid or payable by such indemnified party as a
result of such losses, claims, damages, judgments, liabilities and expenses (i)
in such proportion as is appropriate to reflect the relative benefits received
by the Company on the one hand and the Underwriters on the other hand from the
offering of the Shares, or (ii) if the allocation provided by clause (i) above
is not permitted by applicable law, in such proportion as is appropriate to
reflect not only the relative benefits referred to in clause (i) above but also
the relative fault of the Company on the one hand and the Underwriters on the
other hand in connection with the statements or omissions which resulted in such
losses, claims, damages, liabilities or expenses, as well as any other relevant
equitable considerations. The relative benefits received by the Company on the
one hand and the Underwriters on the other hand shall be deemed to be in the
same proportion as the total proceeds from the offering (net of underwriting
discounts and commissions but before deducting expenses) received by the Company
bear to the total underwriting discounts and commissions received by the
Underwriters, in each case as set forth in the table on the cover page of the
Prospectus. The relative fault of the Company on the one hand and the
Underwriters on the other hand shall be determined by reference to, among other
things, whether the untrue statement or alleged untrue statement of a material
fact or the omission or alleged omission to state a material fact relates to
information supplied by the Company or by the Underwriters, and the parties'
relative intent, knowledge, access to information and opportunity to correct or
prevent such statement or omission. The amount paid or payable by a party as a
result of the losses, claims, damages, judgments, liabilities and expenses
referred to above shall be deemed to include any legal or other fees or expenses
reasonably incurred by such party in connection with investigating or defending
any claim or action.
 
     The Company and the Underwriters agree that it would not be just and
equitable if contribution pursuant to this Section 8(d) were determined by pro
rata allocation or by any other method of allocation (even if the Underwriters
were treated as one entity for such purpose) that does not take account of the
equitable considerations referred to in this Section 8(d). Notwithstanding the
provisions of this Section 8(d), no Underwriter indemnified party shall be
required to contribute any amount in excess of the amount by which the total
price at which the Shares underwritten by such Underwriter indemnified party and
distributed to the public were offered to the public exceeds the amount of any
damages which such Underwriter indemnified party otherwise has been required to
pay by reason of such untrue statement or alleged untrue statement or omission
or alleged omission. No person guilty of fraudulent misrepresentation (within
the meaning of Section 11(f) of the Act) shall be entitled to contribution from
any person who was not guilty of such fraudulent misrepresentation. The
Underwriters' obligations to contribute pursuant to this Section 8 are several
in proportion to their respective underwriting commitments and are not joint.
 
     The statements under the caption "Underwriting" in the Prospectus (to the
extent such statements relate to an Underwriter) constitute the only information
furnished to the Company in writing by such Underwriter expressly for use in the
Registration Statement, any Preliminary Prospectus or the Prospectus.
 
     (e) The indemnity and contribution agreements contained in this Section 8
and the representations, warranties and covenants of the Company contained in
this Agreement shall remain in full force and effect, regardless of any
investigation made by or on behalf of any Underwriter indemnified party or by or
on behalf of any Company indemnified party, and shall survive any termination of
this Agreement or the issuance and delivery of the Shares. Subject to the
provisions of Section 8(b) and Section 8(c), the Company and each Underwriter
agree promptly to notify the other of the commencement of any litigation or
proceeding against it in connection with the issuance and sale of the Shares or
in connection with the Registration Statement or the Prospectus.
 
     10. Notices.  Except as otherwise herein provided, all statements,
requests, notices and agreements shall be in writing or by telegram and, if to
the Underwriters, shall be sufficient in all respects if delivered or sent to
Dillon, Read & Co. Inc., 535 Madison Avenue, New York, New York 10022,
Attention: Syndicate
 
                                       14

   16
 
Department, and if to the Company, shall be sufficient in all respects if
delivered or sent to the Company at the offices of the Company at 3400 Central
Expressway, Santa Clara, California 95051, Attention: Chief Financial Officer.
 
     11. Construction.  THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD TO PRINCIPLES
OF CONFLICTS OF LAW. THE SECTION HEADINGS IN THIS AGREEMENT HAVE BEEN INSERTED
AS A MATTER OF CONVENIENCE OF REFERENCE AND ARE NOT A PART OF THIS AGREEMENT.
 
     12. Parties at Interest.  The Agreement herein set forth has been and is
made solely for the benefit of the Underwriters, the Company, the Underwriter
indemnified parties and the Company indemnified parties, and their respective
successors, assigns, executors and administrators. No other person, partnership,
association or corporation (including a purchaser, as such purchaser, from any
of the Underwriters) shall acquire or have any right under or by virtue of this
Agreement.
 
     13. Counterparts.  This Agreement may be signed by the parties in
counterparts which together shall constitute one and the same agreement among
the parties.
 
     If the foregoing correctly sets forth the understanding among the Company
and the Underwriters, please so indicate in the space provided below for such
purpose, whereupon this letter and your acceptance shall constitute a binding
agreement among the Company and the Underwriters, severally.
 
                                          Very truly yours,
 
                                          VISX, INCORPORATED
 
                                          By:
 
                                            ------------------------------------
                                              Name:
                                              Title:
 
Accepted and agreed to as of
the date first above written,
on behalf of themselves,
PaineWebber Incorporated
and the other several
Underwriters named in
Schedule A
 
DILLON, READ & CO. INC., as
Managing Underwriter
 
By:
 
    --------------------------------------------------------
      Name:
      Title:
 
                                       15

   17
 
                                   SCHEDULE A
 

NUMBER OF UNDERWRITER FIRM SHARES - --------------------------------------------------------------------------------- ----------- Dillon, Read & Co. Inc........................................................... PaineWebber Incorporated......................................................... --------- Total............................................................................ 2,500,000 =========
18 SCHEDULE B STOCKHOLDERS WHO HAVE EXECUTED LOCK-UP AGREEMENTS