Hi Trisk,
I ride with prescription Transitions lenses and love them! I bought a pair of Oakley frames at my eye doctor's, and they ordered transitions lenses with my prescription. They even billed it on my VSP plan, so it was cheaper than buying a pair of non-prescription sunglasses at the bike store.
What do a I like? Well, it's nice not having to put contact lenses in before riding -- they get so dried out! I also find that the lenses get dark enough for me. During today's ride, the weather changed from overcast to raining to sunny and back again. I never had to remove my glasses because they were too dark.
They also wrap around a little bit, so I get protection from the wind coming in when I'm descending. When I rode with my regular glasses, my eyes would tear up big time while I was descending from wind irritation.
What don't I like? Hmmm...sometimes when I'm wearing the glasses while not riding, they seem a little distorted, probably because of the curve in the lenses. It really isn't a problem when I ride, though. I also sometimes miss the peripheral vision correction you get with contacts. My frames don't wrap around as much as others, so I still find that I get a little wind irritation during some descents.
All in all, I'm really happy that I bought my prescription glasses with Transitions lenses.
-- Melissa
I'll get back on the bike soon, I promise!