Just a warning on low Rx's. He wears -1.00 and - 0.75 and could see NO DIFFERENCE between any of his other glasses that are conventionally surfaced. Don't just jump on the bandwagon except for high astigmats /or high Rx's.
Just a warning on low Rx's. He wears -1.00 and - 0.75 and could see NO DIFFERENCE between any of his other glasses that are conventionally surfaced. Don't just jump on the bandwagon except for high astigmats /or high Rx's.
low power Spheres in a conventional POW frame? Well, if this is true, then if you expected a WOW, you've come to the wrong place.
Here's where you should suggest these lenses:
Cylinder 0.75 and over.
High pupil heights
Non-default POW values
Custom, non-standard base curves.
There lies the fertile fields for WOW.
Watch yourself! You're getting lost in the hype!
Barry
But doesn't it strike you as odd that the vast majority of freeform SV and progressives arent available over a 4.00 cylinder?
I cannot speak for other free-form lens manufacturers, but Carl Zeiss Vision establishes the recommended prescription ranges based upon what we can accurately and reliably produce, not upon what you can "dial" into the machine.
While it may be technically possible for a free-form generator to cut (or at least attempt to cut) higher prescription ranges in some cases, the final quality of the finished surface may not meet satisfy our quality guidelines.
Thickness and cut-out limitations of the lens blank may also be factors that limit the recommended prescription range in some cases.
Darryl J. Meister, ABOM
Could be. It's the in and out you got to worry 'bout. (Sorry, I've been listening to this: http://www.youtube.com/watch?v=d0nERTFo-Sk&feature=player_embedded#)
There are may variables with digitally surfaced lenses. The size of the tool used, moment and control of the moment of the tool axis etc. The software to control these functions is quite complex and not optimized by all equipment manufacturers, that is the reason you will get different results using the same lens design software on certain jobs.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Bookmarks