I used to wear a pair of Rudy Project sunglasses for cycling. Then I bought a pair of polarized Oakleys for everyday use and was super-impressed. The lens clarity is excellent, like there's nothing at all in front of your eyes even though I have the darkest lens color available. After that I bought a pair of Flak Jackets for cycling and am extremely happy with them. The unobtainium that they use to make the nosepads and stem sleeves really does keep the glasses from slipping down, so they fit much better and give much better protection than my old glasses did. I love my Oakleys.

I wear the very dark gray polarized lenses most of the time, and switch to yellow for dusk/sunless conditions.