[twobyfour]

Your biggest challenge might be not the frames but the lens curvature. Lenses these days are ordered from a catalog of standard prescriptions.

Unusually strong prescriptions sometimes have to be special-ordered because they aren't kept in stock, but AFAIK they're still not custom-ground. Or at least they're still machine-ground from standard blanks.

If you want a lens with unusual curvature, you'd need to start with a blank that supports that curvature - which may not exist. And the grinding machines may also be unable to work with that curvature (hand-grinding, besides being immensely more expensive, will be less consistent in its result).

And then you'll have the problem of fitting the lens securely into a frame that's designed for one with lesser curvature. Heck, even my (moderate prescription) sunglasses suffer from poor lens fit.

I'm not saying it can't be done; just that there are a lot of obstacles to what you're looking for.