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                                                                     EXHIBIT 4.3

                      AMENDMENT NO. 3 TO RIGHTS AGREEMENT


        This Amendment No. 3 to Rights Agreement (this "Amendment") is made and
entered into as of this 11th day of June, 2002 by and between ChromaVision
Medical Systems, Inc., a Delaware corporation (the "Company"), and Computershare
Investor Services LLC, a Delaware limited liability company, who has succeeded
to the rights and obligations of Harris Trust Company of California, a trust
company organized under the laws of the State of California, as Rights Agent
(the "Rights Agent"), and is effective immediately prior to the execution and
delivery of that certain Securities Purchase Agreement, dated as of June 13,
2002 between the Company, Safeguard Delaware, Inc., a Delaware corporation and
Safeguard Scientifics, Inc., a Delaware corporation (the "Securities Purchase
Agreement") but only if the Securities Purchase Agreement is executed and
delivered.

        The Company and the Rights Agent are parties to a Rights Agreement dated
as of February 10, 1999, as amended by certain Amendments to the Rights
Agreement dated as of June 21, 1999 and September 28, 2000, respectively
(collectively the "Rights Agreement"). The parties now desire to amend the
Rights Agreement on the terms set forth herein. All capitalized terms not
otherwise defined in this Amendment shall have the meanings set forth in the
Rights Agreement, and all inconsistencies between this Amendment and the Rights
Agreement shall be resolved in favor of this Amendment.

        1. Definition of 15% Stockholder. The definition of "15% Stockholder" in
Section 1 of the Rights Agreement is hereby amended to read in full as follows:

        "15% Stockholder" shall mean any Person that Beneficially Owns 15% or
more of the Voting Shares of the Company then outstanding; provided, however,
that the term "15% Stockholder" shall not include:

        (i) an Exempt Person;

        (ii) any Person that would not otherwise be a 15% Stockholder but for a
        reduction in the number of outstanding Voting Shares resulting from a
        stock repurchase program or other similar plan of the Company or from a
        self tender offer of the Company, which Plan or tender offer commenced
        on or after the date hereof; provided, however, that the term "15%
        Stockholder shall include such Person from and after the first date upon
        which (A) such Person, since the date of the commencement of such plan
        or tender offer, shall have acquired Beneficial Ownership of, in the
        aggregate, a number of Voting Shares of the Company equal to 1% or more
        of the Voting Shares of the Company then outstanding and (B) such
        Person, together with all Affiliates and Associates of such Person,
        shall Beneficially own 15% or more of the Voting Shares of the Company
        then outstanding;

        (iii) any Person that would not otherwise be a 15% Stockholder but for
        its Beneficial Ownership of Rights;

        (iv) any Person that is the Beneficial Owner of 15% or more of the
        outstanding Voting Shares of the Company as of February 10, 1999 and
        thereafter has continued to be the Beneficial Owner of at least 15% of
        the Voting Shares of the Company then outstanding; provided however,
        that the term "15% Stockholder" shall include such Persons from and
        after the first date upon which

                        (A) such person since February 10, 1999 shall have
                acquired, without the prior approval of the Board of Directors
                of the Company, Beneficial Ownership of additional Voting Shares
                excluding (y) up to 1,351,607 shares acquired and to be acquired
                by Safeguard Scientifics, Inc. in the aggregate from Technology
                Leaders, L.P., Technology Leaders Offshore C.V., Technology
                Leaders II L.P. and Technology Leaders II Offshore C.V. after
                February 10, 1999, and (z) shares and warrants to purchase
                shares to be acquired by Safeguard Delaware, Inc., a
                wholly-owned subsidiary of Safeguard Scientifics, Inc. from the
                Company, as approved by a the Board of Directors of the Company
                on September 27, 2000, and provided



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                        (B) such Person, together with all Affiliates and
                Associates of such Person shall Beneficially Own not more than
                40% of the Voting Shares of the Company then outstanding;

        (v) any Exempted Group; or

        (vi) either of Safeguard Delaware, Inc. or with respect to Safeguard
        Delaware, Inc., (a) any other Person that at such time directly or
        indirectly through one or more intermediaries Controls, or is Controlled
        by, or is under common Control with, Safeguard Delaware, Inc., (b) any
        Person beneficially owning or holding, directly or indirectly, 10% or
        more of any class of voting or equity interests of Safeguard Delaware,
        Inc. or any Subsidiary or any corporation of which Safeguard Delaware,
        Inc. and its Subsidiaries beneficially own or hold, in the aggregate,
        directly or indirectly, 10% or more of any class of voting or equity
        interests and (c) any Person who would otherwise become a 15%
        Stockholder as a result of any voting agreements, proxies or other
        voting arrangements with respect to the Common Stock and/or the Series D
        5% Cumulative Convertible Preferred Stock of the Company (the Series D
        Preferred Stock") between Safeguard Delaware, Inc. or any of its
        affiliates and any or all of the present holders of the Series D
        Preferred Stock, the officers of the Company or the directors of the
        Company relating to approval of the matters to be voted upon at the
        special meeting of stockholders to be held pursuant to the Securities
        Purchase Agreement, it being the intention of the Board of Directors by
        this Amendment that no Rights have been exercised or become exercisable
        in connection with the "Transaction Documents" (as defined in the
        Securities Purchase Agreement), the related Stock Purchase Agreement to
        be entered into by the Company, Safeguard Delaware, Inc. and the present
        holders of the Series D Preferred Stock or the transactions contemplated
        thereby or by the Securities Purchase Agreement, including without
        limitation any of the voting arrangements referred to above.

As used in this definition, "Control" means the possession, directly or
indirectly, of the power to direct or cause the direction of the management and
policies of a Person, whether through the ownership of voting securities, by
contract or otherwise.

In calculating the percentage of the outstanding Voting Shares that are
Beneficially Owned by a Person for purposes of this definition, Voting Shares
that are Beneficially Owned by such Person shall be deemed outstanding, and
Voting Shares that are not Beneficially owned by such Person and that are
subject to issuance upon the exercise or conversion of outstanding conversion
rights, exchange rights, warrants or options shall not be deemed outstanding.
Any determination made by the Board of Directors of the Company as to whether
any person is or is not a 15% Stockholder shall be conclusive and binding upon
all holders of Rights."

        2. Definition of Exempted Group. Section 1 of the Rights Agreement is
hereby amended to add the following definition:

        "Exempted Group" shall mean any group (as defined in Rule 13d-5
        promulgated under the Exchange Act as in effect on the date hereof)
        consisting of Safeguard Scientifics, Inc., its Affiliates and
        Associates, and incuVest LLC, a limited liability company and its
        Affiliates and Associates, but only so long as (i) Safeguard
        Scientifics, Inc. and its Affiliates and Associates Beneficially Own
        more than a majority of the Voting Shares of the Company Beneficially
        Owned in the aggregate by Safeguard Scientifics, Inc., its Affiliates
        and Associates, incuVest LLC and its Affiliates and Associates and (ii)
        Safeguard Scientifics, Inc., its Affiliates and Associates, incuVest LLC
        and its Affiliates and Associates do not Beneficially Own in the
        aggregate more than 45% of the Voting Shares of the Company then
        outstanding."

        3. Continued Effectiveness. Except as amended hereby, the Rights
Agreement shall remain in full force and effect.

        4. Counterparts. This Amendment may be executed in two or more
counterparts, each of which will be deemed an original and all of which together
will constitute one and the same document.



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


                                            CHROMAVISION MEDICAL SYSTEMS, INC.


Attest:

By: /s/ Allison Wlodyka                     By: /s/ Kevin C. O'Boyle
   -------------------------------             ---------------------------------
   Name: Allison Wlodyka                       Name: Kevin C. O'Boyle
   Title: Assistant Secretary                  Title: Senior Vice President of
                                                      Operations

Dated:  June 11, 2002                       Dated:  June 11, 2002

                                               COMPUTERSHARE INVESTOR
                                               SERVICES LLC

Attest:

By: /s/ Michael Goedecke                    By: /s/ John A. Castellanos
   -------------------------------             ---------------------------------
   Name: Michael Goedecke                      Name  John A. Castellanos
   Title: Business Development                 Title: Relationship Manager



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