I have a REALLY bad astigmatism (It's been nearly 6 months and I still don't have contacts that fit!!!). But I was lucky enough to get wrap sunglasses through Rudy Project. They are the kind that have inserts in them - my astigmatism is so bad that I can't wear Oakleys or other brands that wrap because they cant get my prescription to work. I love these sunglasses! They offer great protection, even when down in the drops. If I'm out riding in my daily wear Oakleys (transition lenses, "flat" frames), it's hard for me to see when in the drops because I'm looking either right into the top of the frame or over it.
I know a lot of people don't like inserts, but it's a plus for me - I bought them as prescription glasses, so the insurance paid for them, but when I'm in contacts, I can wear the same sunglasses by just popping out the insert. One less pair of sunglasses I have to buy!
They fit under my helmet, don't slide down my face when I look down, I wear them playing softball and for triathlons. Not that I'm a commercial, I am just really excited to have athletic Rx sunglasses that stay on my face no matter what I'm doing.

http://www.rudyprojectusa.com/produc...yles/rydon.htm