I'm going through a similar experience. My riding sunglasses are a Ray Ban model with some correction for distance and a line bi-focal. They work for my vision both near and far....I can read the GPS and tach. However, I'd like a more wrap around sunglass for better eye protection. My research shows that wrap around lenses don't work well with bi-focals, line or progressive. Apparently there will be a lot of distortion on the outer edges. I've discovered that WileyX
http://www.wileyx.com/index.aspx and Oakley
http://ca.oakley.com/store make their own prescription lenses that can have quite a curve to them. Oakley has a great selection of frames, but combined with a prescription lens, become very expensive for Canadians. WileyX on the other hand, have some Motorcycle specific frames and are reasonably priced with their prescription. There aren't any WileyX dealers in Canada, but they have offered me a prescrption pair that I can order on line. Placing an order on line with out trying some frames on for fit, bothers me somewhat. Some measurements I gave a WileyX rep suggests I have a medium/small face, so she recomended the AirRage Frame. Any one with a medium/small face have experience with WileyX sunglasses, especially the AirRage style? I'm also considering giving up the bi-focal prescription and just go for the distance correction I need. Any thoughts on that choice?