Solution: use your previous prescription (assuming you got new glasses & frames) and use RainX. Works like a charm. I don't have any of those fancy schmancy lenses, so there isn't much trouble with the potential ruining of the glasses. I didn't want to use my current glasses though for fear that it may have ill effects after long periods of time. Your optical shop won't be happy that you're doing it. It worked for me though, and I can see with them, so I still use them. Rain runs off immediately and I don't fog. Also, you can wear a baseball cap under your helmet and the brim will keep you mostly dry, but I don't know how well that would work in a downpour.