The lens on my glasses have gotten really scratched up and I need a new pair. Would this new pair of glasses be covered at all under our insurance plan? If so, how do I claim it? And can I only buy from certain optical stores? Thanks!

Not unless things change from last year.
If you want to see your benefits, just google "mcmaster health insurance" and follow the links from there.

Unfortunately, I think it does not. I recall we had referendum during this past year's election which included an expansion of the current health plan such as inclusion of optometry related payments or contraceptives and it did not pass.