Actually that is not a myodisc it is a lenticular g. The difference is a myodisc has flat carrier on both sides a lenticular has a convex carrier on the concave side.
It was not that long ago that any lab could create this masterpiece today you would be hard pressed to find one that even knows what it is or how to make it.
Oh wow, thanks for teaching me something new!
Actually it is a myodisc. The base curve is obviously minus with the back base toric and cross curves minus as well. The outer perimeter curve on the back side is convex (plus) to reduce edge thickness giving a minus lenticular viewing Rx area of about 35mm.
If made several in my career by using xtra thick CR-39 blanks. This is what was used on this order
Last edited by PRECISIONLAB; 08-23-2022 at 04:32 PM.
Actually that's a pretty crappy frame choice.
By definition a myodisc has flat curves to reduce the thickness if you use a convex curve it is a lenticular. The Toric surface would be on the front if you if were on the the back you end up with an oval field not acceptable to most people.
Meh, it doesn't really matter that much with the lenticular. The thickest spot is going to be at the edge of the bowl which isn't going to be effected by frame size. Even if the A measurement were 6mm less, not a lot would be gained in thickness reduction, minor weight reduction though. Better to get the frame to fit the noggin well, so they stay in place.
I thought vertex control would be a problem with a plastic frame.
You know, I'm a big joker with that blue roll stuff, but I may have lucked onto something useful.
You know how, if you have a super myopic doofus in a big old sunglass frame because...doofus...and the lab uses polycarb because you asked them to, and they do some overly aggressive bevel/roll and the edge doesn't sun tint and you have clear circles? (That's good opticianry ordering that...ask me how I know.)
Well, a solution (other than using 1.6 which would have eliminated the problem, right?) is to put a nice flash mirror on the front surface to mask that effect. Hell, flash mirror is pretty cool for everyone (except flat base curve high myopes because it looks weird all flat like that)(and for front-surface multifocals that are wavy-looking)!
So...how about a flash mirror on a non-tinted myodisc (the actual, factual "blue roll technique") just to disguise that special magic bowl effect on the back? Would it help? What do you think?
The dreaded white ring is still very visible - even with a full mirror. Flash too. Ask me how *I* know. :) (And no, they weren't even poly!)
I like the thought process, but unfortunately, I fear these pts have enough visual difficulties already - adding even more reflection and unhelpful artifacts into their world would be a non-starter on a lenticular/myodisc/blend/whatever. Blue roll it is! ;)
Last edited by Uilleann; 08-25-2022 at 10:38 AM.
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