<PAGE>

                                                                   Exhibit 10.12

                              SIXTH AMENDMENT TO
                        MULTICURRENCY CREDIT AGREEMENT


         THIS SIXTH AMENDMENT TO MULTICURRENCY CREDIT AGREEMENT (this
"Amendment") is entered into as of March 30, 2001 among SOLA INTERNATIONAL INC.,
a Delaware corporation (the "Company"), those certain Subsidiaries of the
Company identified on the signature pages hereto, including American Optical
Lens Company, a Delaware corporation, as Guarantor (the "Guarantor"), the Banks
party hereto and BANK OF AMERICA, N.A. (formerly Bank of America National Trust
and Savings Association), as Agent for the Banks (the "Agent"). Capitalized
terms used herein and not otherwise defined shall have the meanings ascribed
thereto in the Credit Agreement (as defined below).


                                   RECITALS
                                   --------

         WHEREAS, the Company and certain Subsidiaries of the Company, as
Borrowers (the "Borrowers"), certain other Subsidiaries of the Company as
Subsidiary Guarantors, the Banks and the Agent entered into that certain
Multicurrency Credit Agreement, dated as of June 14, 1996 (as amended by that
certain Consent and Amendment No. 1 to Multicurrency Credit Agreement, dated as
of March 31, 1997, that certain Amendment No. 2 to Multicurrency Credit
Agreement, dated as of November 5, 1997 (the "Second Amendment"), that certain
Amendment No. 3 to Multicurrency Credit Agreement, dated as of March 4, 1998
(the "Third Amendment"), that certain Fourth Amendment to Multicurrency Credit
Agreement, dated as of October 31, 2000 (the "Fourth Amendment") and that
certain Fifth Amendment to Multicurrency Credit Agreement and Waiver dated as of
January 31, 2001, and as otherwise amended or modified from time to time, the
"Credit Agreement");

         WHEREAS, the original Subsidiary Guarantors were released pursuant to
the Second Amendment and the Third Amendment, and certain additional Borrowers
were added pursuant to the terms thereof;

         WHEREAS, the Guarantor executed a Guaranty Agreement, dated as of
January 31, 2001 (the "Guaranty"), guaranteeing to the Banks the full payment
                       --------
and performance of the obligations of the Borrowers under the Credit Agreement
and the other Loan Documents;

         WHEREAS, the Company and the Guarantor executed a Security Agreement,
dated as of January 31, 2001, (the "Security Agreement") whereby they pledged
                                    ------------------
certain assets to the Banks as security for their obligations under the Credit
Agreement;

         WHEREAS, Section 7.14 of the Credit Agreement requires the Borrowers,
upon the failure of certain conditions set forth therein, to pledge additional
assets to the Banks no later than March 31, 2001;

         WHEREAS, the Borrowers have requested that the Majority Banks amend
Section 7.14 of the Credit Agreement;
<PAGE>

         WHEREAS, the Majority Banks are willing to amend Section 7.14 of the
Credit Agreement based upon and subject to the terms and conditions specified in
this Amendment.

         NOW, THEREFORE, in consideration of the premises and the mutual
covenants contained herein, and for other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties hereto
agree as follows:


                                   AGREEMENT
                                   ---------

                                   SECTION 1
                         AMENDMENT TO CREDIT AGREEMENT
                         -----------------------------

         1.1   New Definition. Section 1.01 of the Credit Agreement is
               --------------
amended to add the following new definition in the appropriate alphabetical
order:

               "Guarantor" means American Optical Lens Company, a Delaware
                ---------
         corporation, as Guarantor under the Guaranty.

         1.2   Additional Collateral. Section 7.14 of the Credit Agreement is
               ---------------------
amended and restated in its entirety to read as follows:

               7.14   Refinancing. If (a) at any time UBS Warburg (or any other
                      -----------
         financial institution acceptable to the Majority Banks) is no longer
         actively involved in leading and arranging a high yield bond offering
         and/or other financing for the Company, in an aggregate amount not less
         than $185,000,000, the proceeds of which shall be used to repay the
         Obligations (the "Refinancing") or (b) subsequent to April 20, 2001,
         the Refinancing has not been consummated, the Borrowers shall, and
         shall cause the Guarantor to, immediately: (i) grant a security
         interest in all of their assets located in the United States not
         previously granted pursuant to the Security Agreement, pursuant to
         documentation reasonably acceptable to the Agent, and to take such
         action as requested by the Agent to perfect such security interests;
         and (ii) deliver such other documents, opinions and financing
         statements in connection therewith as reasonably requested by the
         Agent.


                                   SECTION 2
                             CONDITIONS PRECEDENT
                             --------------------

         2.1   Conditions Precedent. This Amendment shall not be effective until
               --------------------
the following conditions have been satisfied or waived by the Majority Banks:

               (a)    Documentation. Receipt by the Agent of copies of this
                      -------------
         Amendment duly executed by the Borrowers, the Guarantor and the
         Majority Banks.

                                       2
<PAGE>

               (b)    Fees. The payment by the Borrowers of an amendment fee of
                      ----
         $5,000 to each Bank that duly executes and delivers this Amendment on
         or before 5:00 p.m., Eastern Standard Time, on Thursday, March 29,
         2001.



               (c)    Legal Expenses. The payment by the Borrowers of all
                      --------------
         reasonable out-of-pocket legal fees and expenses of the Agent.


                                    SECTION 3
                                  MISCELLANEOUS
                                  -------------

         3.1   Ratification and Reaffirmation of Loan Documents. The term
               ------------------------------------------------
"Credit Agreement" and "Agreement" as used in each of the Loan Documents shall
hereafter mean the Credit Agreement as amended by this Amendment. Except as
herein specifically agreed, the Credit Agreement and the other Loan Documents
are hereby ratified and confirmed and shall remain in full force and effect
according to their terms, including, without limitation, the Guaranty and the
Security Agreement. The Borrowers and the Guarantor acknowledge and confirm
that: (a) the Borrowers' obligation to repay the outstanding principal amount of
the Loans and to reimburse the Issuing Bank for any drawing on a Letter of
Credit is unconditional and, as of the date hereof, not subject to any offsets,
defenses or counterclaims, (b) the Agent and the Banks have performed fully all
of their respective obligations under the Credit Agreement and the other Loan
Documents, (c) by entering into this Amendment, the Banks do not waive or
release any term or condition of the Credit Agreement or any of the other Loan
Documents or any of their rights or remedies under such Loan Documents or
applicable law or any of the obligations of any of the Borrowers thereunder
except as expressly set forth herein and (d) the liens established by the
Security Agreement and the guaranty obligations set forth in the Guaranty are in
full force and effect.

         3.2   Authority/Enforceability. Each of the Borrowers, the Guarantor,
               ------------------------
the Agent and the Banks party hereto represents and warrants as follows:

               (a)    It has taken all necessary action to authorize the
         execution, delivery and performance of this Amendment.

               (b)    This Amendment has been duly executed and delivered by
         such Person and constitutes such Person's legal, valid and binding
         obligations, enforceable in accordance with its terms, except as such
         enforceability may be subject to (i) bankruptcy, insolvency,
         reorganization, fraudulent conveyance or transfer, moratorium or
         similar laws affecting creditors' rights generally and (ii) general
         principles of equity (regardless of whether such enforceability is
         considered in a proceeding at law or in equity).

               (c)    No consent, approval, authorization or order of, or
         filing, registration or qualification with, any court or Governmental
         Authority or third party is required in connection with the execution,
         delivery or performance by such Person of this Amendment.

                                       3
<PAGE>

         3.3   Representation and Warranties. The Borrowers and the Guarantor
               -----------------------------
represent and warrant to the Banks that:

               (a)  the representations and warranties of (i) the Borrowers
         set forth in Article VI of the Credit Agreement and (ii) the Guarantor
         set forth in the Guaranty, are true and correct as of the date hereof
         except for those that specifically relate to an earlier date; and

               (b)  no event has occurred and is continuing which constitutes
         a Default or an Event of Default (other than as specifically waived
         hereby).

         3.4   General Release. In consideration of the Majority Banks entering
               ---------------
into this Amendment, the Borrowers and the Guarantor hereby release the Agent,
the Banks, and the Agent's and the Banks' respective officers, employees,
representatives, agents, counsel and directors from any and all actions, causes
of action, claims, demands, damages and liabilities of whatever kind or nature,
in law or in equity, now known or unknown, suspected or unsuspected to the
extent that any of the foregoing arises from any action or failure to act under
the Credit Agreement, the Guaranty or any of the other Loan Documents on or
prior to the date hereof.

         3.5   Counterparts/Telecopy. This Amendment may be executed in any
               ---------------------
number of counterparts, each of which when so executed and delivered shall be an
original, but all of which shall constitute one and the same instrument.
Delivery of executed counterparts by telecopy shall be effective as an original
and shall constitute a representation that an original will be delivered if
requested.

         3.6   Further Assurances. Subject to Section 7.14 of the Credit
               ------------------
Agreement (as amended by this Amendment), each of the Borrowers and the
Guarantor agrees to promptly take such action, upon the request of the Agent, as
is necessary to carry out the intent of this Amendment, the Collateral Documents
and the Loan Documents, including, but not limited to, such actions as are
necessary to ensure that the Banks have a perfected security interest in the
Collateral subject to no Liens other than Permitted Liens.

         3.7   GOVERNING LAW. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS
               -------------
OF THE PARTIES HEREUNDER SHALL BE GOVERNED BY AND CONSTRUED AND INTERPRETED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.


                 [remainder of page intentionally left blank]

                                       4
<PAGE>

                                                                   Exhibit 10.12

         IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
duly executed and delivered by their proper and duly authorized officers or
attorneys-in-fact as of the day and year first above written.

BORROWERS:                       SOLA INTERNATIONAL INC.,
----------
                                 a Delaware corporation

                                 By:    /s/ Steven M. Neil
                                     ---------------------------------------
                                 Name   Steven M. Neil
                                        ------------------------------------
                                 Title: CFO
                                        ------------------------------------


                                 SOLA INTERNATIONAL HOLDINGS LTD.
                                 (ACN007719708), a South Australian corporation

                                 SOLA OPTICAL HOLDINGS (U.K.) LIMITED,
                                 an English corporation

                                 SOLA OPTICAL S.A., a French corporation

                                 SOLA OPTICAL GMBH, a German corporation

                                 SOLA HONG KONG LIMITED,
                                 a Hong Kong corporation

                                 SOLA ADC LENSES LIMITED,
                                 an Irish corporation

                                 SOLA OPTICAL ITALIA S.P.A.,
                                 an Italian corporation

                                 SOLA OPTICAL JAPAN LIMITED,
                                 a Japanese corporation

                                 SOLA OPTICAL SINGAPORE PTE. LTD.,
                                 a Singapore corporation

                                 SOLA IFSC, an Irish
                                 unlimited liability company

                                 AMERICAN OPTICAL COMPANY
                                 INTERNATIONAL AG, a  Switzerland corporation

                                 By:    /s/ Steven M. Neil
                                     ---------------------------------------
                                 Name   Steven M. Neil
                                        ------------------------------------
                                 Title: CFO
                                        ------------------------------------
                                        of each of the foregoing entities
<PAGE>

                     SIGNATURE PAGE TO SIXTH AMENDMENT TO
                        MULTICURRENCY CREDIT AGREEMENT
                           SOLA INTERNATIONAL, INC.


   GUARANTOR:                           AMERICAN OPTICAL LENS COMPANY,
   ---------
                                        a Delaware corporation


                                 By:    /s/ Steven M. Neil
                                     ---------------------------------------
                                 Name   Steven M. Neil
                                        ------------------------------------
                                 Title: CFO
                                        ------------------------------------
<PAGE>

                     SIGNATURE PAGE TO SIXTH AMENDMENT TO
                        MULTICURRENCY CREDIT AGREEMENT
                           SOLA INTERNATIONAL, INC.




   BANKS:                          BANK OF AMERICA, N.A.
   -----                           (formerly Bank of America National Trust
                                   and Savings Association)
                                   individually in its capacity as a Bank
                                   and in its capacity as Agent



                                   By:   /s/ Henry Y. Yu
                                       ------------------------------
                                   Name:  Henry Y. Yu
                                         ----------------------------
                                   Title: Managing Director
                                          ---------------------------
<PAGE>

                            THE BANK OF NOVA SCOTIA


                            By:  /s/ Jed Richardson
                               -----------------------------------------
                            Name:  Jed Richardson
                                 ---------------------------------------
                            Title:  Director
                                  --------------------------------------
<PAGE>

                              FLEET NATIONAL BANK


                              By:
                                 ---------------------------------------
                              Name:
                                   -------------------------------------
                              Title:
                                    ------------------------------------
<PAGE>

                              ABN AMRO BANK N.V.


                              By:  /s/ Jamie Dillon
                                 ---------------------------------------
                              Name:  Jamie Dillon
                                   -------------------------------------
                              Title: Senior Vice President
                                    ------------------------------------


                              By:  /s/ R. Clay Jackson
                                  --------------------------------------
                              Name:  R. Clay Jackson
                                    ------------------------------------
                              Title:  Senior Vice President
                                      ----------------------------------
<PAGE>

                        COMMERZBANK AKTIENGESELLSCHAFT,
                      New York and Grand Cayman Branches


                        By: /s/ Christian Jagenberg
                            --------------------------------------------
                        Name: Christian Jagenberg
                              ------------------------------------------
                        Title: Senior Vice President and Manager
                               -----------------------------------------


                        By:  /s/ Steven F. Larsen
                             ------------------------------------------
                        Name:  Steven F. Larsen
                               ----------------------------------------
                        Title:  Senior Vice President
                                ---------------------------------------
<PAGE>

                    WELLS FARGO BANK, NATIONAL ASSOCIATION


                    By:  /s/ Michael Chacon
                       ------------------------------------------------
                    Name:  Michael Chacon
                         ----------------------------------------------
                    Title:  Vice President
                           --------------------------------------------
<PAGE>

                                  BNP PARIBAS


                                  By:   /s/ Debra Wright
                                      ----------------------------------
                                  Name:  Debra Wright
                                        --------------------------------
                                  Title:  Vice President
                                         -------------------------------


                                  By:  /s/ Jeffrey S. Kajisa
                                     ----------------------------------
                                  Name:  Jeffrey S. Kajisa
                                       --------------------------------
                                  Title:  Vice President
                                        -------------------------------
<PAGE>

                      THE DAI-ICHI KANGYO BANK, LIMITED,
                      New York Branch


                      By:  /s/ Ying Yang
                         ----------------------------------------------
                      Name:  Ying Yang
                           --------------------------------------------
                      Title:   Account Officer
                            -------------------------------------------