DNR - I know Oakley makes some prescription glasses (though it may be restricted on the amount of correction).
Both my Revision and ESS glasses have inserts for vision correction (which I need and use if I'm not wearing contacts). See here (
http://www.esseyepro.com/Profile---I...12_detail.html) for an example (the image is of goggles, but the same principle applies for normal shooting glasses as well.