STATEMENT OF THE GOAL:
I would like to devise my own "Rx program" for my basic sunglass collection, much like our Maui Jim and Oakley collections have their own Rx programs.
They've specified their power limitations on each frame, probably based on base cuves that will work with the frame front, and hopefully weight and thickness limitations.
I need to be able to put the proper limitations on lesser-expensive sunglass frames that I carry for cost-sensitive patients.
With the popularity of 8-base wrap frames, I would like to know how to limit the Rx's to those that would physically fit the frame and would work optically.
WHAT I THINK I ALREADY KNOW:
Obviously, any frame with a +6.00 base lens will work for a wide range of Rx lenses, like an ophthalmic frame would.
My thinking is this: I assume 8-base frames can take 6-10 base lenses and still not get too much frame distortion and too many glazing problems. The optimal Rx range for that base curve range in CR39 would be -2.00 to high plus powers. If I am willing to sacrifice optics somewhat, I could expand that range in minus to about -4.00, I believe.
USING ASPHERICS AND HIGHER INDICES
I also realize that 1.6 indices, like polycarb, which we use in these frames, cause the lens to be flattened by about 15%, compounding the problem, let alone aspheric design in minus, which flattens it even further. I feel aspheric design in higher plus lenses is desireable to reduce weight in these large eyesize frames, but I'm not sure it's a good idea, because these wrap frames also induce horizontal lens tilt and prism. Will an aspheric plus lens be worse than a sphere would?
(Another factor I'd like to correct for is the blasted lens tilting-effect, which changes the effective power and prism of the lens. I'll forget about that for now.)
I would appreciate any comments, including those that say I may be trying too hard!
I would like to devise my own "Rx program" for my basic sunglass collection, much like our Maui Jim and Oakley collections have their own Rx programs.
They've specified their power limitations on each frame, probably based on base cuves that will work with the frame front, and hopefully weight and thickness limitations.
I need to be able to put the proper limitations on lesser-expensive sunglass frames that I carry for cost-sensitive patients.
With the popularity of 8-base wrap frames, I would like to know how to limit the Rx's to those that would physically fit the frame and would work optically.
WHAT I THINK I ALREADY KNOW:
Obviously, any frame with a +6.00 base lens will work for a wide range of Rx lenses, like an ophthalmic frame would.
My thinking is this: I assume 8-base frames can take 6-10 base lenses and still not get too much frame distortion and too many glazing problems. The optimal Rx range for that base curve range in CR39 would be -2.00 to high plus powers. If I am willing to sacrifice optics somewhat, I could expand that range in minus to about -4.00, I believe.
USING ASPHERICS AND HIGHER INDICES
I also realize that 1.6 indices, like polycarb, which we use in these frames, cause the lens to be flattened by about 15%, compounding the problem, let alone aspheric design in minus, which flattens it even further. I feel aspheric design in higher plus lenses is desireable to reduce weight in these large eyesize frames, but I'm not sure it's a good idea, because these wrap frames also induce horizontal lens tilt and prism. Will an aspheric plus lens be worse than a sphere would?
(Another factor I'd like to correct for is the blasted lens tilting-effect, which changes the effective power and prism of the lens. I'll forget about that for now.)
I would appreciate any comments, including those that say I may be trying too hard!
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