Oakley Plutonite lenses are ANSI Z87.1 compliant. You could use them for airsoft skirmish play, though I would highly recommend a wrap-around frame rather than simple eyeglass-style. Though they do qualify for airsoft eye protection, I personally wouldn't use them for financial reasons - why ruin a hundered-something dollar pair of designer eye-wear when you can purchase a $10-$15 pair of "shooter" glasses that is also ANSI Z87.1 compliant. At least if they get shot, scratched, or otherwise ruined from gameplay, you won't be fretting over purchasing another pair.
I personally recommend Crossfire eyewear (
http://www.crossfiresafety.com) They have a bunch of different Oakley-esque styles, cost between $10-$15 a pair, and will stop a .22 penetrating @ 45ft (I've seen the test pairs with the shots myself - that's over 1300 FPS). I believe they are wholesale only, but can be found at many sport and outdoor shops.