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

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                                   FORM 8-A/A

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

                       CHROMAVISION MEDICAL SYSTEMS, INC.
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             (Exact Name of Registrant as Specified in its Charter)

               Delaware                                   75-2649072
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(State of Incorporation or Organization)       (IRS Employer Identification no.)

         33171 Paseo Cerveza,
    San Juan Capistrano, California                          92675
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(Address of Principal Executive Offices)                  (Zip Code)

If this form relates to the registration of a class of securities pursuant to
Section 12(b) of the Exchange Act and is effective pursuant to General
Instruction A.(c), please check the following box. [ ]

If this form relates to the registration of a class of securities pursuant to
Section 12(g) of the Exchange Act and is effective pursuant to General
Instruction A.(d), please check the following box. [X]


Securities Act registration statement file number to which this form relates:
                                    0-022677
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Securities to be registered pursuant to Section 12(g) of the Act:

      Title of Each Class                       Name of Each Exchange on Which
      to be so Registered                       Each Class is to be Registered
   -------------------------                    ------------------------------

      Rights to Purchase
   Series C Preferred Stock,
   par value $.01 per share                         Nasdaq National Market
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Securities to be registered pursuant to Section 12(b) of the Act:

                                      None
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                                (Title of Class)

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                       CHROMAVISION MEDICAL SYSTEMS, INC.
                 INFORMATION REQUIRED IN REGISTRATION STATEMENT

Item 1.  Description of Registrant's Securities to be Registered.

                  On June 23, 1999 ChromaVision Medical Systems, Inc.
("ChromaVision") amended its Stockholder Rights Plan, which had been adopted in
March 1999. The Stockholder Rights Plan provides for the distribution of rights
to purchase additional shares of capital stock of ChromaVision in the even any
person, entity or group acquires beneficial ownership of 15% or more of the
outstanding Voting Shares of ChromaVision. "Voting Shares" is defined in the
Plan to mean Common Stock and any other shares of capital stock of the Company
entitled to vote generally in the election of directors or to approve any
merger, consolidation, sale of all or substantially all assets of the Company,
liquidation, dissolution or winding up. Presently the only Voting Shares
outstanding are the shares of Common Stock.

                  The Plan included an exception for acquisitions of shares by
persons, entities or groups who, as of February 10, 1999, were the beneficial
owner of more than 15% of the outstanding shares of Common Stock of the Company.
(These beneficial owners are refered to below as "Existing 15% Owners.") That
exemption in the Plan applied only if (1) the Existing 15% Owner continued to
own at least 15% of the Voting Shares of the Company and (2) did not acquire
additional Voting Shares which would cause the Existing 15% Owner's beneficial
ownership of Voting Shares to exceed 30% of the number of shares outstanding.

                  The amendment to the Plan makes two changes. First, it exempts
from the provision described above the acquisition by Safeguard Scientifics,
Inc., which is the only Existing 15% Owner known to the Company, of up to
1,351,607 additional shares of Common Stock in the aggregate from Technology
Leaders, L.P., Technology Leaders Offshore C.V., Technology Leaders II L.P. and
Technology Leaders II Offshore CV. Second, the amendment to the Plan increases
the percentage of outstanding Voting Shares which an Existing 15% Owner can
acquire from 30% to 40%.

Item 2.  Exhibits

         1.       Rights Agreement, dated as of February 10, 1999, between
                  ChromaVision Medical Systems, Inc. and Harris Trust Company of
                  California, as Rights Agent (incorporated by reference to
                  ChromaVision's registration statement on Form 8-K (commission
                  file no. 0-022677) filed March 12, 1999).


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         2.       Amendment to Rights Agreement dated June 23, 1999 between
                  ChromaVision and Harris Trust Company of California, as Rights
                  Agent (incorporated by reference to ChromaVision's
                  registration statement on Form 8-K (commission file no.
                  0-022677) filed July 2, 1999).

         3.       Certificate of Designations of Series C Preferred Stock
                  (incorporated by reference to ChromaVision's registration
                  statement on Form 8-K (commission file no. 0-022677) filed
                  March 12, 1999).

                                    SIGNATURE

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

Date:  July 2, 1999                    CHROMAVISION MEDICAL SYSTEMS, INC.


                                       By:      /s/ Douglas S. Harrington, M.D.
                                                --------------------------------
                                       Name:    Douglas S. Harrington, M.D.
                                       Its:     Chief Executive Officer
                                                (Duly Authorized Officer of the
                                                Registrant)


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