EXHIBIT 32.1

CERTIFICATION PURSUANT TO SECTION 906
OF THE SARBANES-OXLEY ACT OF 2002

CERTIFICATION OF CHIEF EXECUTIVE OFFICER AND CHIEF FINANCIAL OFFICER

PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Elizabeth H. Dávila, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of Sarbanes-Oxley Act of 2002, that the Quarterly Report of VISX, Incorporated on Form 10-Q for the quarterly period ended March 31, 2005 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that information contained in such Quarterly Report fairly presents in all material respects the financial condition and results of operations of VISX, Incorporated.

/s/ Elizabeth H. Dávila

Elizabeth H. Dávila

Chief Executive Officer

May 6, 2005

I, Derek A. Bertocci, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of Sarbanes-Oxley Act of 2002, that the Quarterly Report of VISX, Incorporated on Form 10-Q for the quarterly period ended March 31, 2005 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that information contained in such Quarterly Report fairly presents in all material respects the financial condition and results of operations of VISX, Incorporated.

/s/ Derek A. Bertocci

Derek A. Bertocci

Chief Financial Officer

May 6, 2005