Sunglasses for commuting? I've recently started commuting via bike to work (6.5mi each way), and am looking for advice on gear... specifically sunglasses (which I find useful to prevent dust in eyes and to help block the ample sun).

Currently I'm using an expensive pair of Oakleys (not meant for riding per-se), but I'm wondering if I should get a specific pair of glasses that are preferred by riders.

Any suggestions on brands or even specific models would be nice.
If you don't want to spend lots of money you can still get the most relevant characteristics in a pair of safety glasses. 

You can find these at just about any hardware store and they:


wrap around, 
are impact resistant, 
block UV, 
don't look half bad
come in clear and tinted (and are cheap enough to get one of each usually)