ive got a patient with a +1450 -475 in both eyes i remember a while back something about a composite lens, im thinkin it was a 1.67 back with a poly front that was ideal for high plus'. Anyone know who makes it or if theyres anything else that would cut thickness. Poly is still just too thick for the poor kid. thanks in advance
You may be thinking of the Behold! lens from PixelOptics. The on line data sheet says that the Rx Range is from +10.00D to -11.00D. The material is a composite of 1.67 and Trivex
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yup that was it but +10 range wont work dangit lol guess well keep him in poly
The composite nature of the lens excludes it from drop ball testing so the lens can be surfaced paper thin at the edges.
You can get better performance and thinner lenses in a higher index material such as 1.71 or 1.74, it's out of range for stock so you'll have to see if your lab can surface the power, but you'll get clean optics and they'll be thin.
Check with Bristolite, I think they may have something to help. If I can find thier web address I'll post it.
http://www.bcdlens.com/about/index.aspx
BRISTOL C & D, INC.
14317 S.W.
142ND AVE.
MIAMI FL 33186
877-255-1181
That lens is begging for a single vision Free Form. Any reason it has to be poly and not hi-index. I know you posted that it was a kid, but at that power, I don't think impact resistance is going to be an issue.....
There are rules. Knowing those are easy. There are exceptions to the rules. Knowing those are easy. Knowing when to use them is slightly less easy. There are exceptions to the exceptions. Knowing those is a little more tricky, and know when to use those is even more so. Our industry is FULL of all of the above.
Unfortunately Freeform has limits: generally +/- 10d and 4d cyl is the limit for almost all freeform generators.
I would not have suggested it if we could not do it. Shamir Autograph II SV range is -16.00 to +16.00 / cyl to -6.00 (No, the +/- 16.00 is NOT total power) in both 1.67 and 1.74. I know I can make it work on a 1.70 as well.Originally Posted by Audiyoda
The limitations are more in the polishing than the generators. And if I had to I could digitally surface a hard tool to match the curves. Might not be perfect, but it would be close enough to work.
And I'm willing to bet anything that ICE-TECH can do it as well.
There are rules. Knowing those are easy. There are exceptions to the rules. Knowing those are easy. Knowing when to use them is slightly less easy. There are exceptions to the exceptions. Knowing those is a little more tricky, and know when to use those is even more so. Our industry is FULL of all of the above.
I stand corrected. But to be fair it's been a long time since I've looked at Freeform specs - when Freeform first hit the market it's specs where what I quoted.
I would also assume that doing something like this in Freeform won't be cheap - whereas Bristolite is a fairly affordable product.
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