Not sure if this will help you but I got it off their college website

Eye exams are not covered by OHIP for most adults between 20-64 years old.

For some patients (19 years and younger, 65 years and older, or those with specific medical conditions) OHIP covers a standard eye exam.

If your optometrist recommends testing that is not covered by OHIP, they will:

inform you of any test before it happens; explain why the test is needed in your situation; outline any additional fees and explain what they are for; discuss the benefits (or risks, if any) associated with the test; and obtain your consent to perform the test.

If you need more clarification you should call any clinic and tell them you have a requisition from walk in clinic you are in ODSP and want to make sure that you will be receiving a standard eye exam covered by OHIP