Hi LaDiverGuy,
Welcome to Scuba Board! I feel your pain when it comes to the issue of less than perfect vision. You see, I am blind as a bat without my glasses or contacts.
When I first got certified, I wrestled with this dilemma for quite a while before making my decision. I decided just to wear my contact lenses while diving and forego the extra expense of purchasing a prescription mask. I wear my contacts for every other activity I participate in, including running, hiking, swimming, and skiing (snow & water) and just about anything else you can think of, so I figured what the heck, diving with contacts is how it will be.
I felt a little bit justified in that decision on the first of our OW dives. One of my classmates had purchased a very nice mask with the prescription ground into the lenses. We were doing a shore dive, and there was a bit of surf. In his effort to get out past the break, my classmate got all turned around and ended up having his mask whisked off his face by the waves.
We all spent about 20 minutes looking for the mask but it was long gone. He was able to borrow our instructor's spare and complete his skills, but he was not a happy camper.
So, to make a long story short, I wear my 4 week disposable lenses when I dive and carry a spare set in my bag so that if something happens and I lose a lens, I don't have to walk around squinting to see where I am going.