I'm nearsighted as well and have always worn contacts during my 10 years of diving. However, last at DEMA (the dive industry trade show) last October I talked to the guys from HydroOptix masks and it turns out my prescription is a natural match for their mask. Their mask is designed to improve the way we see underwater (you can more accurately judge distance, size, etc), but essentially, the domed lenses of the mask will serve as a presciptive mask for me. I haven't had a chance to get in the water with it yet, but the physics behind it sound really interesting.
You can read more about the HydroOptix mask at:
http://www.sportdiver.com/product.js...clientID=33048
Laura C.S. Walker
Online Director, Sport Diver