Designer and specialty sunglasses, like the kinds used for sports, cost more than most sunglasses, but you'll find all kinds of fashion glasses for sale at affordable prices. Watch the UV ratings carefully and you'll be fine.

Unless you already know which frame shapes look good on you, go shopping and try on as many styles as possible.
 
If you can get permission to walk outside with glasses on, do it, so that you can find out how they actually work in the sunlight!

So when are you picking up one?