Which style will fit best over dark prescripsion glasses? And also not fog up.

The oakley A frame is waaaaaaaaay too small for glasses.they wont fog up but maybe go with a lighter lense like pink iridium or VR28 also a HI Yellow lense you can always buy and return back country guarantee complete satisfaction and an unlimited lifetime warranty. If at any time -- now, next month, in 30 years -- you're not 100% satisfied, send your gear back for a full refund or exchange. No questions asked.Also, depending on the size of your glasses, you might want to consider the Oakley Wisdom's or Oakley Crowbar's. These are a little bigger goggle that has more room inside for you glasses to fit freely. I'm not familiar with wearing glasses and goggles at the same time, but none of the Oakley goggles that you pick should fog up. I'm not sure about your glasses staying fog free though. The goggles do have good venting, so I would guess that as long as you're moving you should be ok. You could also buy an anti fog spray for your glasses and then you should have no problems at all.