I prefer clear lenses, although since I wear prescription glasses, my choices are limited anyways.
Since I work in a lab anyways, I simply ordered a separate pair of Uvex safety glasses:
http://www.vwrsp.com/catalog/product/index.cgi?object_id=0012191&class_id=5005994
These are very comfortable, and protect your eyes from the front, as well as from the top and both sides. Also, you won't build up nearly as much fog, since they're better ventilated.
Back when I used contact lenses, I tried using ordinary shooting safety glasses (Remington brand), until a piece of brass that ricocheted off the wall, ended up slipping through the side spaces of my safety glasses. Not pleasant, but I did remember to put the gun down before taking care of that piece of brass! It took several days before the burn mark went away.