For daytime rides I wear sunglasses with amber lenses. Generic Blue Blocker lenses but in a non-stupid looking frame. I'm cheap, and while even cheap smoke lenses block plenty of light, they also greatly reduce visibility. I'll even wear the ambers on foggy days as they provide more contrast.

At nights if it's cold enough I wear safety glasses with clear lenses and frame. If it's nice out, nothing. Though I should, with all the insects in the summer.