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                                                                     EXHIBIT 4.2

                            SERIES B PREFERRED STOCK
                               PURCHASE AGREEMENT

        This Series B Preferred Stock Purchase Agreement (this "Agreement") is
entered into as of October 21, 1999 (the "Effective Date") by and among
Ophthalmic Imaging Systems, a California corporation (the "Company" or "OIS"),
and Premier Laser Systems, Inc., a California corporation ("Premier").

                                    RECITALS

        WHEREAS, the Company, Premier and Ophthalmic Acquisition Corporation, a
California corporation and a subsidiary of Premier ("Premier Sub"), and their
respective boards of directors, are negotiating an Agreement and Plan of
Reorganization (the "Merger Agreement"), whereby, upon requisite shareholder and
board approval, OIS will be merged with and into Premier Sub (the "Merger"),
with OIS becoming the surviving corporation and each share of OIS common stock
converting into shares of Premier Class A common stock at the exchange ratio set
forth in the Merger Agreement;

        WHEREAS, Premier has held more than 51% of the outstanding common stock
of OIS and therefore a majority vote;

        WHEREAS, OIS owes certain amounts to Premier including, but not
necessarily limited to, interest owed, expenses for services provided and a note
in the amount of $500,000 (all such debt collectively referred to herein as the
Company's "Debt Owed");

        WHEREAS, approximately thirty-five persons, including approximately
thirty current employees of OIS, presently hold approximately 1,600,000 options
to purchase OIS common stock at an exercise price ranging from $0.63 to $4.50
per share (the "Employee Options"), many of which are already vested; and

        WHEREAS, the Company desires to sell to Premier, and Premier wishes to
purchase from Company, in exchange for canceling part of the Company's Debt Owed
and pursuant to the terms and conditions hereof, that amount of the Company's
Series B Preferred Stock (the "Series B Preferred") necessary to preserve
Premier's majority vote despite the exercise of Employee Options by one or more
persons, and without triggering the preferred share purchase rights under the
Rights Agreement dated December 31, 1997, as amended, between OIS and American
Securities Transfer, Inc. (the "Rights Agreement");

                                    AGREEMENT

        NOW, THEREFORE, in consideration of the foregoing recitals and the
mutual promises, covenants and conditions hereinafter set forth, the parties
hereto agree as follows:



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                                    ARTICLE 1

                         REPRESENTATIONS OF THE COMPANY

        The Company represents, warrants and agrees as follows:

        1.1     Power and Capacity; Authorization. OIS is a corporation duly
organized, validly existing and in good standing under the laws of those
jurisdictions where failure to be in good standing or to so qualify would have a
material adverse effect on OIS. OIS has full corporate power and authority to
execute and deliver this Agreement and to consummate the transactions
contemplated hereby. The execution and delivery of this Agreement and the
consummation of the transactions contemplated hereby have been duly and validly
authorized by the Company's Board of Directors and no other corporate
proceedings by OIS are necessary to authorize this Agreement or to consummate
the transactions so contemplated. This Agreement has been duly and validly
executed and delivered by OIS and, assuming this Agreement constitutes a valid
and binding obligation of Premier, constitutes a valid and binding agreement of
OIS, enforceable against OIS in accordance with its terms (subject, as to the
enforcement of remedies, to applicable bankruptcy, reorganization, insolvency,
moratorium and similar laws affecting creditors' rights, and, with respect to
the remedy of specific performance, equitable doctrines applicable thereto).

        1.2     No Conflicts. The execution, delivery and performance of this
Agreement by OIS will not (a) constitute a breach or violation of any provisions
of the Company's Articles of Incorporation or Bylaws, (b) result in a violation
of any law, rule, ordinance, regulation, order, judgment or decree by which OIS
is bound, or (c) conflict with or result in a material breach of or default
under any mortgage, lien, lease, license, permit, agreement, contract or
instrument to which OIS is a party or by which OIS is bound, which conflict,
breach or default would have a material adverse effect on the ability of OIS to
perform its obligations under this Agreement.

        1.3     Preferred Stock. The Company has a total of 20,000,000
authorized shares of Preferred Stock, $0.01 par value per share, 2,000 of which
are designated Series B Preferred Stock and none of which are issued and
outstanding. The Company has reserved 2,000 shares of Common Stock for possible
issuance upon the conversion of the shares of Series B Preferred to be issued
hereunder (the "Conversion Shares"). The Series B Preferred, when issued, sold
and delivered in accordance with the terms of this Agreement, will be duly and
validly issued, fully paid and non-assessable. The Conversion Shares have been
duly and validly reserved for issuance and, upon issuance in accordance with the
terms of the Certificate of Determination, will be duly and validly issued,
fully paid and non-assessable.

        1.4     Certificate of Determination. The Company has duly adopted a
Certificate of Determination of Preferences of Series B Preferred Stock of
Ophthalmic Imaging Systems in such form as is attached hereto as Exhibit A (the
"Certificate of Determination") and has obtained all necessary approvals from
its Board of Directors and shareholders, if necessary, and has duly filed the
Certificate of Determination with the California Secretary of State.



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        1.5     Rights Agreement. The Company has taken and will continue to
take all necessary action to ensure that none of the transactions contemplated
by this Agreement will cause (i) Premier or any of its affiliates to become an
Acquiring Person (as defined in the Rights Agreement) for purposes of the Rights
Agreement, or (ii) otherwise affect in any way the Rights under the Rights
Agreement, including by causing such Rights to separate from the underlying
shares or by giving such holders the right to acquire securities of any party
hereto or by triggering provisions of the Rights Agreement that may give rise to
a Distribution Date (as such term is defined in the Rights Agreement).

                                    ARTICLE 2

                           REPRESENTATIONS OF PREMIER

        Premier represents, warrants and agrees as follows:

        2.1     Power and Capacity; Authorization. Premier is a corporation duly
organized, validly existing and in good standing under the laws those
jurisdictions where failure to be in good standing or to so qualify would have a
material adverse effect on Premier. Premier has full corporate power and
authority to execute and deliver this Agreement and to consummate the
transactions contemplated hereby. The execution and delivery of this Agreement
and the consummation of the transactions contemplated hereby have been duly and
validly authorized by Premier's Board of Directors and no other corporate
proceedings by Premier are necessary to authorize this Agreement or to
consummate the transactions so contemplated. This Agreement has been duly and
validly executed and delivered by Premier and, assuming this Agreement
constitutes a valid and binding obligation of OIS, constitutes a valid and
binding agreement of Premier, enforceable against Premier in accordance with its
terms (subject, as to the enforcement of remedies, to applicable bankruptcy,
reorganization, insolvency, moratorium and similar laws affecting creditors'
rights, and, with respect to the remedy of specific performance, equitable
doctrines applicable thereto).

        2.2     No Conflicts. The execution, delivery and performance of this
Agreement by Premier will not (a) constitute a breach or violation of any
provisions of Premier's Articles of Incorporation or Bylaws, (b) result in a
violation of any law, rule, ordinance, regulation, order, judgment or decree by
which Premier is bound, or (c) conflict with or result in a material breach of
or default under any mortgage, lien, lease, license, permit, agreement, contract
or instrument to which Premier is a party or by which Premier is bound, which
conflict, breach or default would have a material adverse effect on the ability
of Premier to perform its obligations under this Agreement.

        2.3     Investigation and Economic Risk. Premier acknowledges that it
has had an opportunity to discuss the business, affairs and current prospects of
the Company with the Company's officers. Premier acknowledges that it is able to
fend for itself in the transactions contemplated by this Agreement and has the
ability to bear the economic risks of its investment pursuant to this Agreement.



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        2.4     Purchase for Own Account. The Series B Preferred and the
Conversion Shares are being acquired by Premier for its own account, not as a
nominee or agent, and not with a view to or in connection with the sale or
distribution of any part thereof.

        2.5     Exempt from Registration and Restricted Securities. Premier
understands that the Series B Preferred and the Conversion Shares will not be
registered under the 1933 Act, on the ground that the sale provided for in this
Agreement is exempt from registration under the Act, and that the reliance of
the Company on such exemption is predicated in part on Premier's representations
set forth in this Agreement. Premier understands that the Series B Preferred and
the Conversion Shares being purchased hereunder are restricted securities within
the meaning of Rule 144 under the 1933 Act and that the Series B Preferred and
the Conversion Shares are not registered and must be held indefinitely unless
they are subsequently registered or an exemption from such registration is
available. It is further understood that each certificate representing (a) the
Series B Preferred, (b) the Conversion Shares, and (c) any other securities
issued in respect of the any of the foregoing upon any stock split, stock
dividend, recapitalization, merger, or similar event shall be stamped or
otherwise imprinted with an appropriate restrictive legend.

                                    ARTICLE 3

                      AGREEMENT TO PURCHASE AND SELL STOCK

        3.1.    Authorization. As of the first Closing (as defined below), the
Company will have authorized the issuance, pursuant to the terms and conditions
of this Agreement, of up to 2,000 shares of the Company's Series B Preferred, no
par value, having the rights, preferences, privileges, and restrictions set
forth in the Certificate of Determination of the Company attached to this
Agreement as Exhibit A.

        3.2.    Purchase of Stock. Subject to the terms and conditions set forth
in this Agreement, the Company agrees to sell, assign, transfer and deliver to
Premier, and Premier agrees to purchase from the Company, fifty (50) validly
issued, fully paid and nonassessable shares of the Company's Series B Preferred
Stock (the "Purchased Stock"), whenever one or more persons (other than Walt
Williams, Daniel Durrie or Randall Fowler) exercise Employee Options to
purchase, in the aggregate, 50,000 shares of Company Common Stock. Premier shall
be entitled to purchase shares of Series B Preferred Stock because of the
exercise of stock options held by Walt Williams, Daniel Durrie and Randall
Fowler (the "Outside Directors") pursuant to that certain Agreement dated
October 21, 1999, between OIS, Premier and the Outside Directors. Any and all
purchases by Premier of Series B Preferred Stock shall be automatic and shall
not require any further action by the parties hereto. Each such purchase shall
be a separate "Closing" for purposes of this Agreement.

        3.3     Price and Consideration. In full consideration for the purchase
by Premier of the Purchased Stock, Premier shall cancel on each Closing that
amount of the Debt Owed then held by Premier in the amount of twenty-five
dollars ($25.00) per share of Series B Preferred Stock purchased by Premier as
Purchased Stock (the "Purchase Price"). Premier shall deliver to OIS written
evidence, in a form acceptable to OIS, showing the cancellation of the
aforementioned indebtedness under the terms of this Agreement.



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        3.4     Stock Certificates. As soon as practicable after each Closing,
OIS will deliver to Premier a certificate representing the Series B Preferred
purchased by Premier, which certificate shall bear appropriate restrictive
legends.

        3.5     Best Efforts and Further Assurances. Each of the parties to this
Agreement shall use its best efforts to effectuate the transactions contemplates
hereby and to fulfill and cause to be fulfilled the terms and conditions set
forth under this Agreement. Each party hereto, at the reasonable request of
another party hereto, shall execute and deliver such other instruments and do
and perform such other acts and things as may be necessary or desirable for
effecting completely the consummation of this Agreement and the transactions
contemplated hereby.

                                    ARTICLE 4

                          CONDITIONS TO THE OBLIGATIONS
                              UNDER THIS AGREEMENT

        4.1     Conditions to the Obligations of the Company and Premier. The
obligations of OIS to sell and Premier to purchase the Purchase Stock pursuant
to this Agreement is conditioned upon: (a) the exercise of Employee Options
resulting in the purchase of at least 50,000 shares of Company Common Stock; and
(b) the representations and warranties made by the Company and Premier herein
shall be true and correct when made, and shall be true and correct as of the
date of each Closing with the same force and effect as if they had been made on
and as of such date, subject to changes contemplated by this Agreement.

                                    ARTICLE 5

                                  MISCELLANEOUS

        5.1     Expenses. Each party to this Agreement shall pay its own costs
and expenses (including all legal fees) relating to this Agreement, the
negotiations leading up to this Agreement and the transactions contemplated by
this Agreement.

        5.2     Amendment. This Agreement shall not be amended except by a
writing duly executed by each party to this Agreement.

        5.3     Entire Agreement. This Agreement, including the exhibits and
other documents delivered pursuant to this Agreement, contain all of the terms
and conditions agreed upon by the parties relating to the subject matter of this
Agreement and supersede all prior and contemporaneous agreements, negotiations,
correspondence, undertakings and communications of the parties, oral or written,
respecting the subject matter hereof.

        5.4     Governing Law. This Agreement shall be governed by, and
construed in accordance with, the laws of the State of California.



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        5.5     Headings. The headings contained in this Agreement are intended
solely for convenience and shall not affect the rights of the parties to this
Agreement.

        5.6     Mutual Contribution. The parties to this Agreement and their
counsel have mutually contributed to its drafting. Consequently, no provision of
this Agreement shall be construed against any party on the ground that that
party drafted the provision or caused it to be drafted.

        5.7     Notices. All notices, requests, demands and other communications
made in connection with this Agreement shall be in writing and shall be deemed
to have been duly given on the date of delivery, if delivered to the persons
identified below, including delivery by facsimile, provided sender receives
telephonic or electronic confirmation of delivery, or three days after mailing
if mailed by certified or registered mail, postage prepaid, return receipt
requested, addressed as follows:

        If to the Company:

               Ophthalmic Imaging Systems
               221 Lathrop Way, Suite I
               Sacramento, CA 95815
               Attention: President
               Facsimile No.:  (916) 646-0207
               Telephone No.:  (916) 646-2020

        With a copy to:

               Gibson, Dunn & Crutcher LLP
               1530 Page Mill Road
               Palo Alto, California 94304
               Attention: Lawrence Calof, Esq.
               Facsimile No.:  (650) 849-5348
               Telephone No.:  (650) 849-5300

        If to Premier:

               Premier Laser Systems, Inc.
               3 Morgan
               Irvine, CA 92618
               Attention:  President and Chief Executive Officer
               Facsimile No.:  (949) 859-5241
               Telephone No.:  (949) 859-0656



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        With a copy to:

               Paul, Hastings, Janofsky & Walker LLP
               695 Town Center Drive, 17th Floor
               Costa Mesa, CA 92626
               Attention:  William J. Simpson, Esq.
               Facsimile No.: (714) 979-1921
               Telephone No.:  (714) 668-6200

Such persons and addresses may be changed, from time to time, by means of a
notice given in the manner provided in this Section.

        5.8     Survival of Representations and Warranties. The respective
representations and warranties of OIS and Premier contained in this Agreement
shall survive the execution, delivery and performance of this Agreement for a
period of one year from the Closing.

        5.9     Waiver. Waiver of any term or condition of this Agreement by any
party shall not be construed as a waiver of any subsequent breach or failure of
the same term or condition, or a waiver of any other term or condition of this
Agreement.

        5.10    Binding Effect; Assignment. The parties agree that this
Agreement shall be binding upon and inure to the benefit of the parties and
their respective successors and assigns. No party to this Agreement may assign
or delegate, by operation of law or otherwise, all or any portion of its rights,
obligations or liabilities under this Agreement without the prior written
consent of all other parties to this Agreement, which they may withhold in their
absolute discretion.

        5.11    Finder's Fees. Each party (a) represents and warrants to the
other party hereto that it has retained no finder or broker in connection with
the transactions contemplated by this Agreement, and (b) hereby agrees to
indemnify and to hold harmless the other parties hereto from and against any
liability for any commission or compensation in the nature of a finder's fee of
any broker or other person or firm (and the costs and expenses of defending
against such liability or asserted liability) for which the indemnifying party
or any of its employees or representatives are responsible.

        5.12    No Third Party Beneficiaries. Nothing in this Agreement shall
confer any rights upon any person or entity which is not a party or an assignee
of a party to this Agreement.

        5.13    Counterparts. This Agreement may be signed in any number of
counterparts with the same effect as if the signatures to each counterpart were
upon a single instrument. All counterparts shall be deemed an original of this
Agreement.



                          [The signature pages follow.]



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        IN WITNESS WHEREOF, the parties have executed this Agreement as of the
date first written above.


                                        OPHTHALMIC IMAGING SYSTEMS:

                                        By /s/ STEVEN VERDOONER
                                           -------------------------------------
                                           Steven Verdooner, President

                                        PREMIER LASER SYSTEMS, INC.:

                                        By /s/ COLETTE COZEAN
                                           -------------------------------------
                                           Colette Cozean, Ph.D.,
                                           President and CEO




                    [Stock Purchase Agreement Signature Page]




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APPENDIX A:  CERTIFICATE OF DETERMINATION