EXHIBIT 32.1

CERTIFICATION OF

PRINCIPAL EXECUTIVE OFFICER

PURSUANT TO 18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Timothy Ruane, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Annual Report of InSite Vision Incorporated on Form 10-K for the annual period ended December 31, 2010 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended and that information contained in such Annual Report of InSite Vision Incorporated on Form 10-K fairly presents, in all material respects, the financial condition and results of operations of InSite Vision Incorporated.

CERTIFICATION OF

PRINCIPAL FINANCIAL OFFICER

PURSUANT TO 18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Louis Drapeau, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Annual Report of InSite Vision Incorporated on Form 10-K for the annual period ended December 31, 2010 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended and that information contained in such Annual Report of InSite Vision Incorporated on Form 10-K fairly presents, in all material respects, the financial condition and results of operations of InSite Vision Incorporated.