My personal reason for getting FAA PPL (and not JAA) is that I fall outside JAA vison standards. Rules are: max -8 dioptries and I have -9.5 in one eye. So there you have it... WIth my glasses/lenses, I have a better eyesight than some of my friends who don't wear correction. Still, I can not fly an airplane, even is my glasses correct me to perfect 100% sight. Strange...
FAA is much more pragmatic on the vision thing: if you have normal sight with glasses, it's ok for them.
LR