Hello I recently got a pair of the Fours and I like them a lot. I just have few questions about them. Does anyone know if they are prescription friendly or do you have to send them off to the Oakley company to have a prescription made for them? Are Oakley Fours the same as the Oakley Mag S (same size or are Mag S smaller)? Lastly does the Oakley Fours come in different sizes? The pair I have fit me nicely and I was going to try to find one more pair. I wanted to make sure before I went hunting for another pair. Thanks for any help or advice.