AMENDMENT TO THE PURCHASE AND SALE AGREEMENT This Agreement, dated as of July 15, 1999 (the "Amendment"), is by and between THERMO VISION CORPORATION, a Delaware corporation ("Vision"), and CORNING OCA CORPORATION, a Delaware corporation ("COCA").

                                                                     Exhibit 2.2

                                                               EXECUTION VERSION



                                AMENDMENT TO THE
                           PURCHASE AND SALE AGREEMENT


      This  Agreement,  dated as of July 15, 1999 (the  "Amendment"),  is by and
between  THERMO  VISION  CORPORATION,  a Delaware  corporation  ("Vision"),  and
CORNING OCA CORPORATION, a Delaware corporation ("COCA").


                                   WITNESSETH

      WHEREAS,  Vision and COCA are  parties to a Purchase  and Sale  Agreement,
dated as of May 12, 1999 (the "Purchase and Sale Agreement"); and

      WHEREAS,  Vision and COCA desire to amend the Purchase and Sale  Agreement
as provided in this Amendment.

      NOW  THEREFORE,  in  consideration  of the  premises  and mutual  promises
contained in this  Agreement  and  intending  to be legally  bound  hereby,  the
parties hereto agree as follows:


1.    The  definition of "Assets" as provided in Section 1.1 of the Purchase and
      Sale Agreement is hereby amended as follows:

      a.     to delete from such definition the asset designated "CMM 000 Xxxxx
            Xxxxx"; and
      b. to add to such  definition  all of the  assets  listed on  Exhibit  1.1
hereto.


2.    Schedules  9.2(a) and 9.2(b) to the Purchase and Sale Agreement are hereby
      amended and restated in their  entirety as set forth in  Schedules  9.2(a)
      and 9.2(b) hereto.

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3.    Except to the limited extent  modified or  supplemented by this Amendment,
      the provisions of the Purchase and Sale  Agreement  shall continue in full
      force and effect as provided therein.

      IN WITNESS WHEREOF, each party has caused this Agreement to be executed on
its behalf by an officer  thereunto duly authorized,  all as of the day and year
first above written.

THERMO VISION CORPORATION                    CORNING OCA CORPORATION

By:  /s/ Xxxxx Xxxx                          By:  /s/ Xxxxx X. Xxxxx
     ----------------------                       -----------------------------
Name:    Xxxxx Xxxx                          Name:    Xxxxx X. Xxxxx
Title:   Presider                            Title:   Vice President




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