TLC VISION CORPORATION FORM 10-K - EXHIBIT 23(a) CONSENT OF INDEPENDENT CHARTERED ACCOUNTANTS We consent to the incorporation by reference in the Registration Statements Form S-8 (No. 333-8162), Form S-8 (No. 333-71532), Form S-8 (No. 333-55480) and Form S-8 (No. 333-62907) of TLC Vision Corporation of our report dated August 15, 2002 with respect to the consolidated financial statements of TLC Vision Corporation included in this Annual Report (Form 10-K) for the year ended May 31, 2002. Toronto, Canada /s/ Ernst & Young LLP August 29, 2002 Chartered Accountants