That hasn't been my experience with prescription lenses. Not all
frames will take a prescription lens, first of all. Prescription
lens won't take too much curvature. If you go with a
fishing/outdoors frame company, they will know what you are talking
about for lens color (Maui Jim, Action Optics, Costa del Mar, etc.).
All you have to do is pick out your frame, choose a lens color, and
send them your prescription. I currently have a pair of Maui Jims
that I simply walked into a local My Eye Doctor location and told
them what frame and lens color I wanted. You are right, they weren't
cheap.
I've tried all the fit overs. For any sight fishing, you MUST
control light from the sides. I've tried the metal clip-ons that are
sold with some frames and they suck - no light control from the
sides and I would get weird double lens glare. You'll get that weird
double lens glare with all of them, but it is minimized with side
control. I didn't like the Fitovers either, because then you have
the weight of two full pairs of glasses on your face. Some the have
now though don't look so bad, but it is still wearing two pairs of
glasses.
Honestly, my favorite are the ugliest - slip in types. They are
cheap ($6-ish), polarized, offer side protection and come in grey,
brown and yellow. I'd keep a pair in the truck and in my fly-fishing
bag, although I would catch a lot of crap for wearing them. Like
these:
