Please title this page. Ask your dr. They are not covered by health care, but there will be no provincial or GST tax. Buy in bulk, and avoid a great deal of tax.
Prices vary widely from grocery stores to pharmacies to opticians.
From our ophthalmologists and opticians, I've only heard that regular UV-blocking sunglasses are fine. I would really like to hear more about how you deal with the lenses. My daughter, who is the same age, gave up the lenses in favor of glasses at age 3. That was around the same time she developed glaucoma which is treated with eye drops 3-4 times a day. I really need encouragement on that subject.