EXHIBIT 10D
COGNEX CORPORATION
Amendment to 1993 Stock Option Plan
          The Cognex Corporation 1993 Stock Option Plan (the “Plan”) is hereby
amended as follows:
          1. Section 11 of the Plan is amended by adding the following after the
last sentence of the paragraph:
“11. TRANSFERABILITY OF OPTIONS
Notwithstanding the foregoing, an optionee may transfer non-qualified Options
granted under this Plan to the optionee’s spouse or children or to a trust for
the benefit of the optionee or the optionee’s spouse or children.”
          2. Except as modified hereby, the Plan is hereby ratified and
confirmed in all respects.
COGNEX CORPORATION
By: \s\ Anthony J. Medaglia, Jr.
Clerk
Adopted by the Board of Directors:
               December 16, 1997