Yes, I agree, trial lens each meridian, and they can learn the added benefit of finding prescribed prism.
Bob
Type: Posts; User: Bob MacNeil; Keyword(s):
Yes, I agree, trial lens each meridian, and they can learn the added benefit of finding prescribed prism.
Bob
Have they used a Bicentric before.... the reading could use some correction.
Bob
Two things, if it's 117 alloy, it would be most helpful to operate below 122 f , when you can make a good low powered sphere, your off axis problem will normally clear up. ...
The frame is ejecting the lens, remind the lab to shape the frame to fit the lens, it will stop popping out. The use of a polariscope will tell the tale.
Bob
I agree, Volker knows his stuff, did specials with him when we were with Imperial.
Bob
Power errors come in any of four different ways: front curve, back curve, lens index, and lens thickness. Rounding of the shop tools for back curve control is often the major problem in powers...
Stock removal is the amount of lens material removed during the surfacing process, for generating and fining, it's done with a dial indicator, in polishing, it's calculated by weight reduction in...
Stock removal in polishing is critical with poly, it's what removes the scratches from the fining process. Consider spindle speed, lens sweep, clamp pressure and cycle timers. Stock removal in...
Glass as a substrate has a better adhesion, on the wear issue, I agree with your comment.
Over the years I have closed down a few glass surfacing lines, labs...
What is the existing Rx, I would think that any Dr. worth their ticket would caution on prism introduced or removed.
Bob
In the lab, prism degrees are how we calculate prism diopters. Prism degrees are angular, we apply the lens index to get the diopterive value you are expecting.
Bob
Good frame selection, aspherics are more important then index selection for high plus Rx work, lab may be having problems with lens diameter knifing out on surfacing chuck ask for 0.5m/m edge at...