The biggest problem with curved frames is the more prescription strength, the thicker the outside edges are on lenses. The new Bob Allen shooting glasses are available in 6 base curve and 8 bases curve. I make all of the Bob Allen Rx lenses and recommend the 6 base to my clients needing any correction. Not that I haven't made some on the 8 base frame successfully, but the user struggles with getting the lenses in and out of the frame when the lense is thicker than the cleat depth. Wanting to look "cool" has a price and its own problems based on curves frames.
Another issue.... the Boyt/Bob Allen company requires the lenses to be made from Polycarb for safty and liability reasons. Poly is 2 Abby clairty ratings down from glass, so having the PD (pupil distance) properly centered is very important. also, having the lenses ZiessAR coated, a gas/heat treatment makes the poly a bit more clear and have the best anti reflection properties available. Makes the lenses so scratch resistant that dropping them in the gravel isn't an issue. To me, seeing the target clearly is far more important than a fashion statement.
Several companies offer quality frames, with conveniece user features. I see no advantages of any other company over the BA's. I also make lenses for other frame manufactures.
Remember, seeing the target clearly from the blur line (trap) to the shot is one of the most important aspects of shooting high average scores. I consider it the most important for me, since I have developed a proper form, found gun fit, and have the gun set up to center targets as it relates to my timing and sight picture preferences.
Shoot'em in the center.
Maltzie