I have two pairs of Tifosi sunglasses. I don't know the exact model name for my first pair, but they came with four different lens. I liked them at first but over time, the nose piece started to wear a groove into my nose on long rides that hurt.

My second pair are these:
http://www.teamestrogen.com/products.asp?pID=20894

They're specifically made for smaller faces, are very light, and have an integrated nose piece that doesn't bother me at all. They are also polaraized and Fototec. I love them so far. I wear gas permeable contacts, and my eyes are very, very sensitive to light. Even on the brightest days, I don't get any eye strain or headaches. I've also ridden with them in some lower light conditions and they've been just fine, too. If it's really gloomy out, I sometimes still opt to wear my other Tifosis with clear lens, but I haven't had to do that much with all the dry, sunny weather we've been having.