Seems to me it has been a long time since we've had an index bump. You know, when a newer higher index plastic comes on the market, displacing all others down the price line.
We need a new 1.9 index plastic. Yup.
Seems to me it has been a long time since we've had an index bump. You know, when a newer higher index plastic comes on the market, displacing all others down the price line.
We need a new 1.9 index plastic. Yup.
We and patients would be better served by embracing and demanding manufacturers to offer lenses made of Tribrid. Much, much larger market for it than a 1.9 index. Plus, do we really need another high CA, brittle material?
Then maybe Essilor can design a PAL designed especially for it.
Should have 1.8 index first. I keep hearing that *someone* is working on it, don't know who though.
"Tribrid"??
Wesley S. Scott, MBA, MIS, ABOM, NCLE-AC, LDO - SC & GA
“As our circle of knowledge expands, so does the circumference of darkness surrounding it.” -Albert Einstein
I can't see much of a market for tribrid myself, despite getting excited whenever something new comes along. I can't think of any situation where I might have used it so far, since it isn't actually particularly light or particularly strong.
Robert, I'm afraid you have been mis-informed about Tribrid. It's light weight ( specific gravity 1.23, Trivex is 1.11, Poly is 1.22) Thinner than trivex (1.60 index compared to trivex 1.53) Abbe of 41 (trivex 45) And it's strong ( Withstands 160 times FDA dropball requirement) It can be surfaced to 1.0 c.t. making it thinner than poly also.Originally Posted by Robert_S
I love Trivex, but Tribrid will give us a great alternative for higher power ranges and could be the end of using poly altogether. (though poly will be around for a long time for cost reasons)
The only advantage it has over poly is better abbe and trivex would be better for 90% of jobs. 1.67 would be thinner in the higher powers where aesthetics come into play. Look, it's a good product, i just don't see much purpose for it.
PPG says 160 times the energy of the standard drop ball test. That's equal to an increase in velocity of the .56 oz. steel ball from about 17 fps to approximately 210 fps (check my math please!). An AR stack will reduce that somewhat, but that's still strong. I wonder how that compares to Trivex?
I have used Spectralite and Finalite frequently in the past until Trivex became available. Finalite has very similar Abbe and density values compared to Tribrid, but the added impact resistance makes this material attractive for many of my chroma sensitive clients who wear high power lenses, and need/want increased level of impact resistance.
Science is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
I always have to laugh when I see the claims about this or that lens being SO much safer than X or Y lens regarding shatter resistance. Look, if you get hit in the face hard enough to shatter ANY lens dispensed in the US (and made to at least minimum impact tolerances) the reality is you've probably got far bigger problems than whether or not your lens is in one piece or several. :) It's like these videos from a new sport start up just up the road from us:
http://edgeeyewear.com/site_us/media.php
I challenge anybody shot in the face like that with a shotgun or .22 to come up smiling afterwards! ;)
I think we're mostly discussing strength with relation to rimless mounting.
will manufacturers guarantee tribrid in the same way they guarantee trivex?
I will try any thinner lens material once.
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