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                                                                      Exhibit 4


                         AMENDMENT TO RIGHTS AGREEMENT

                 AMENDMENT, dated as of September 28, 1993, to the Rights
Agreement dated as of May 18, 1989 by and between Allergan, Inc., a Delaware
corporation (the "Company"), and First Chicago Trust Company of New York, a New
York corporation, as rights agent (the "Rights Agent").

                 WHEREAS, the name of the Rights Agent was changed to "First
Chicago Trust Company of New York"; and

                 WHEREAS, the Company and the Rights Agent have heretofore
executed and entered into the Rights Agreement, and, pursuant to the Rights
Agreement, the Company and the Rights Agent may from time to time supplement or
amend the Rights Agreement in accordance with the provisions of Section 27
thereof; and

                 WHEREAS, acts and things necessary to make this Amendment a
valid agreement according to its terms have been done and performed, and the
execution and delivery of this Amendment by the Company and the Rights Agent
have been in all respects duly authorized by the Company and the Rights Agent.

                 NOW, THEREFORE, in consideration of the foregoing premises and
mutual agreements set forth in the Rights Agreement and this Amendment, the
parties hereby agree as follows:

                 1.       The first paragraph of the Rights Agreement is hereby
                 amended to read as follows:

                 "This Agreement, dated as of May 18, 1989, between ALLERGAN,
                 INC., a Delaware corporation (the "Company"), and FIRST 
                 CHICAGO TRUST COMPANY OF NEW YORK, a New York corporation
                 (the "Rights Agent")..."

                 2.       Section 7(a) of the Rights Agreement is hereby
                 amended to read as follows:

                          First, clause (i) of the first sentence of Section
                          -----
7(a) shall read in its entirety as follows:

                          "The close of business on the Final Expiration Date
                          (as such term is hereinafter defined)."

                          Second, the following sentence shall be added
                          ------
after the first sentence of Section 7(a):
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                          "The Final Expiration Date shall mean the date of the
                          annual meeting of stockholders in 1997 (the "1997
                          Meeting"), unless a proposal requiring extension of
                          the Final Expiration Date to the annual meeting of
                          stockholders in the year 2000 (the "2000 Meeting")
                          shall have received the affirmative vote of a
                          majority of the shares voting thereon at the 1997
                          Meeting, in which case the Final Expiration Date
                          shall be extended to the 2000 Meeting."

                 3.       Section 24 of the Rights Agreement is hereby amended
                          to read as follows:

                          First, the following sentence shall be added after
                          -----
the title of Section 24:

                          "The Rights may be redeemed by action of the Board of
                          Directors pursuant to subsection (a)(i) or (a)(ii) of
                          this Section 24 or by Stockholder action pursuant to
                          subsection (a)(iii) of this Section 24 and shall not
                          be redeemed in any other manner."

                          Second, the following subsection (a)(iii) shall be
                          ------
added after subsection (a)(ii) of Section 24:
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                          "(iii)  (1) In the event (i) the Company receives an
                          Offer from any Offeror (as such terms are hereinafter
                          defined), and (ii) within 60 days after such receipt
                          (such sixtieth day being referred to herein as the
                          "Offer Date"), the Board of Directors has not either
                          (x) redeemed all but not less than all of the then
                          outstanding Rights or (y) approved an alternative
                          transaction which the Board of Directors has
                          determined to be financially superior for the holders
                          of shares of Common Stock other than the Offeror and
                          its Affiliates, then the Board of Directors shall
                          call a special meeting of stockholders (the "Special
                          Meeting") for the purpose of voting on a precatory
                          resolution requesting the Board of Directors to
                          accept such Offer, as such Offer may be amended or
                          revised by the Offeror from time to time to increase
                          the price per share to be paid to holders of shares
                          of Common Stock (the "Resolution").  The Board of
                          Directors shall select a date for the Special Meeting
                          and shall use its best efforts to ensure that the
                          Special Meeting actually be held on such date, which
                          date shall be not later than the later of (A) the
                          earliest date after the Offer Date on which it is
                          reasonably practicable to arrange a Special Meeting
                          and (B) the date of any meeting of stockholders
                          already scheduled as of the Offer Date; provided,
                          however, that if (x) such other meeting shall have
                          been called for the purpose of voting on a precatory
                          resolution with respect to another Offer and (y) the
                          Offer Date shall be not later than 15 days after the
                          date such other Offer was received by the Company,
                          then both the Resolution and such other resolution
                          shall be voted on at such meeting and such meeting
                          shall be deemed to be the Special Meeting.  The Board
                          of Directors shall set a date for determining the
                          stockholders of record entitled to notice of and to
                          vote at the Special Meeting in accordance with the
                          Company's Certificate of Incorporation and By-Laws
                          and with applicable law.  At the Offeror's request,
                          the Company shall include in any proxy soliciting
                          material prepared by it in connection with the
                          Special Meeting proxy soliciting material submitted
                          by the Offeror; provided, however, that the Offeror
                          shall by written agreement with the Company contained
                          in or delivered such request have indemnified the
                          Company against any and all liabilities resulting
                          from any misstatements, misleading statements and
                          omissions contained in the Offeror's proxy soliciting
                          material and have agreed to pay the Company's
                          incremental costs incurred as a result of including
                          such material in the Company's proxy soliciting
                          material. Notwithstanding the foregoing, no Special
                          Meeting shall be held from and after such time as any
                          Person becomes an Acquiring Person, and any Special
                          Meeting scheduled prior to such time and not
                          theretofore held shall be cancelled.

                                        (2)     If at the Special Meeting the
                          Resolution receives the affirmative vote of a
                          majority of the Voting Power outstanding as of the
                          record date of the Special Meeting, then all of the
                          Rights shall be redeemed by such stockholder action
                          at the Redemption Price, effective immediately prior
                          to the consummation of any tender or exchange offer
                          (provided that such offer is consummated prior to 60
                          days after the date of the Special Meeting) pursuant
                          to which any Person offers to purchase all of the
                          shares of Common Stock held by Persons other than
                          such Person and its Affiliates at a price per share
                          in cash and/or at an exchange ratio which is
                          financially superior to the cash price and/or the
                          exchange ratio contained in the Resolution approved
                          at the Special Meeting; provided, however, that the
                          Rights shall not be redeemed at any time from and
                          after such time as any Person becomes an Acquiring
                          Person.

                                        (3)     Nothing contained in this
                          subsection (iii) of this Section 24 shall be deemed
                          to be in derogation of the obligation of the Board of
                          Directors of the Company to exercise its fiduciary
                          duty.  Without limiting
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         the foregoing, nothing contained herein shall be construed to suggest
         or imply that the Board of Directors shall not be entitled to reject
         any Offer, or to recommend that holders of shares of Common Stock
         reject any tender or exchange offer, or to take any other action
         (including, without limitation, the commencement, prosecution, defense
         or settlement of any litigation and the submission of additional or
         alternative Offers or other proposals to the Special Meeting) with
         respect to any Offer or any tender or exchange offer that the Board of
         Directors believes is necessary or appropriate in the exercise of such
         fiduciary duty.

                                        (4)     Nothing in this subsection
                          (iii) of this Section 24 shall be construed as
                          limiting or prohibiting the Company or any Offeror
                          from proposing or engaging, at any time, in any
                          acquisition, disposition or other transfer of any
                          securities of the Company, any merger or
                          consolidation involving the Company, any sale or
                          other transfer of assets of the Company, any
                          liquidation, dissolution or winding-up of the
                          Company, or any other business combination or other
                          transaction, or any other action by the Company or
                          such Offeror; provided, however, that the holders of
                          Rights shall have the rights set forth in this
                          Agreement with respect to any such acquisition,
                          disposition, transfer, merger, consolidation, sale,
                          liquidation, dissolution, winding-up, business
                          combination, transaction or action.

                                        (5)     An "Offer" shall mean a written
                          proposal delivered to the Company by any Person (an
                          "Offeror"), which proposal:

                                        (A)      provides for the acquisition
                          at the same price of all of the outstanding shares of
                          Common Stock held by any Person other than the
                          Offeror and its Affiliates;

                                        (B)      in an offer all or partially
                          for cash consideration, states that the Offeror has
                          obtained written financing commitments from
                          recognized financing sources, and/or has on hand cash
                          or cash equivalents, for the full amount of all
                          financing necessary to consummate the Offer;
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                                        (C)      if an offer all or partially
                          for consideration other than cash, (i) provides for
                          any non-cash consideration to consist only of
                          securities which are listed and trading on the New
                          York Stock Exchange and (ii) is determined by the
                          Board of Directors of the Company to be one of a
                          series of transactions which will provide
                          tax-deferred treatment for the holders of shares of
                          Common Stock other than the Offeror and its
                          Affiliates;

                                        (D)      is not subject to any
                          financing, funding or similar condition, nor any
                          condition relating to completion of or satisfaction
                          with any due diligence or similar investigation and
                          otherwise provides for usual and customary terms and
                          conditions; and

                                        (E)      requests the Company to call a
                          special meeting of the holders of Common Stock for
                          the purpose of voting on a precatory resolution
                          requesting the Board of Directors to accept such
                          Offer and contains a written agreement of the Offeror
                          to pay (or share with any other Offeror) at least
                          one-half of the Company's costs of such special
                          meeting (exclusive of the Company's costs of
                          preparing and mailing proxy material for its own
                          solicitation)."
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                          Third, the first sentence of Subsection 24(b) shall
                          -----
be amended to read in its entirety as follows:

                          "In the case of a redemption permitted under Section
                          24(a)(i) or Section 24(a)(iii), immediately upon the
                          action of the Board of Directors of the Company
                          ordering the redemption of the Rights pursuant to
                          Section 24(a)(i), or upon the effectiveness of the
                          redemption of the Rights pursuant to Section
                          24(a)(iii), evidence of which shall have been filed
                          with the Rights Agent, and without any further action
                          and without any notice, the right to exercise the
                          Rights will terminate and the only right thereafter
                          of the holders of Rights shall be to receive the
                          Redemption Price."

                          Fourth, the third sentence of Subsection 24(b) shall
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be amended to add the following after the words "Within ten days after the
action of the Board of Directors ordering any such redemption":

                          "pursuant to Section 24(a)(i) or (ii) or the
                          effectiveness of the redemption of the Rights
                          pursuant to Section 24(a)(iii)"

                          Fifth, the sixth sentence of subsection 24(b) shall
                          -----
be amended to add the following after the reference therein to Section 24(a)(i)
or (ii):

                          "or (iii)"

                 4.       The second sentence of Section 26 is hereby amended
so that the address shall read in its entirety as follows:

                          "First Chicago Trust Company of New York
                          P.O.B. 2532, Mail Suite 4690
                          Jersey City, New Jersey
                          07303-2532

                          Attention:  Client Administration"
                          ----------

                 5.       Section 28 of the Rights Agreement is hereby amended
so that the parenthetical clause in the penultimate sentence thereof shall read
in its entirety as follows:

                          "(including, subject to Section 24(a)(iii), a
                          determination to redeem or not redeem the Rights or
                          to amend the Agreement)".
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                 IN WITNESS WHEREOF, the parties hereto have caused this
Amendment to be duly executed and their respective corporate seals to be
hereunto affixed and attested, all as of the day and year first above written.

                                                
                                                   ALLERGAN, INC.


                                                   By:_____________________________
                                                      Name:
                                                      Title:


ATTEST:                    


- ---------------------------
Name:
Title:
                                                   FIRST CHICAGO TRUST COMPANY OF NEW YORK


                                                   By:_____________________________
                                                      Name:
                                                      Title:

ATTEST:                    


- ---------------------------
Name:
Title: