If you have an ipad, there is a great app called glasses.com. You take a video of your face (in the mirror) and some measurements and then you can 'try on' lots of different styles and colors. There is a selection of sunglasses too. You can filter by style, brand, color, price etc and mark your favorites. Then you can save and share the photos.

I've been thinking about getting new glasses so it was fun to play with different styles.