Oakley O Frames Bar F'ing None!! I ordered mine directly from Oakley for around $30, then ordered a nice iridium lens for another $30, but you can get darker lenses for only $5. Most comfortable, best choice of lenses and very scratch resistant, but the tear-offs are easy insurance to a clean view. Once you go Oakley, nothing else comes close.
They're single lens and that's all you really need. Dual lens are good for cold climates and activities like skiing or snowmobiling where the temp varies a lot. You won't need that for quads unless you live in a cold climate and ride your quad in the snow all winter.
I'll second that. I wear them too. I wear glasses and they even fit right over them, beats buying a OTG (over the glasses) type of goggle where options are limmited.
You wouldn't hit a guy with glasses would you?