CR-39 vs. Polycarbonate

[Michael22]

I think this is where most of the people who sell poly are at. If they were the same cost and availability I wouldn't hesitate to put many of my customers in only trivex.

I can barely even upsell people to buy polycarbonate in the market I'm in, bringing up trivex lenses and trying to explain the value to them is just such a no go with the difference in price. Odds are they are already in poly or high index, and are gonna stay that way

[drk]

My cost on Trivex is higher, too (AS IF I get enough private pay...)..but yeah, my 90% VCP crowd pays an inordinate amount more.

[silverton38]

I find a coated CR39 is much better than Poly with a light prescription. CR39 is clearer and more scratch resistant. If it 2.75+- or below it is pretty thin anyways. The strength does not matter much because the frame will probably break well before the lens ever does.

[Uilleann]

I find a coated CR39 is much better than Poly with a light prescription. CR39 is clearer and more scratch resistant. If it 2.75+- or below it is pretty thin anyways. The strength does not matter much because the frame will probably break well before the lens ever does.

In a "light prescription", literally no human can tell the difference. Science & math bear this out as has been shown here numerous times before.

[Michael22]

I've mostly chosen to put as many people in poly/trivex as possible just for the sake of safety, and if a patient chooses to go with CR-39 or a HI lens I make sure to let them know that these lenses can shatter into pieces if impacted. I don't think anybody actually notices the difference between them, and it brings in more money selling them as a standard.

[Uilleann]

Remember that in the US, the FDA mandates all ophthalmic lenses must meet minimum impact resistance requirements (with no thought given to actual Rx accuracy of course). The impact risk (and UV as well) is far more minimal than the majority of dispensers imply to pts. As a group, we should be much more honest about that. *shrug*

[NAICITPO]

Remember that in the US, the FDA mandates all ophthalmic lenses must meet minimum impact resistance requirements (with no thought given to Rx accuracy of course). The impact risk (and UV as well) is far more minimal than the majority of dispensers imply to pts. As a group, we should be much more honest about that. *shrug*

+1

Plus when you put coatings on top of the poly/trivex the impact resistance goes down.

[KrystleClear]

Not sure if OP is still reading this thread, but Laramy-K Optician Works has some great videos on Youtube covering the differences in all the lens materials. They also have a video where they test the impact resistance of poly and trivex. I really can't recommend them enough.

I heard in California, dispensers are now supposed to inform patients/customers that polycarbonate contains a carcinogen? Also, don't use poly with transitions for a bifocal/trifocal lens in a grooved semi rimless frame. The layers can separate. I learned this the hard way with a disgruntled patient.

I think people spend too much time hating on poly and forget the downsides of higher index materials, like 1.74. It deserves a little hate too.

[Michael22]

Not sure if OP is still reading this thread

I am! I actually watched that video a few days ago. It was very interesting!

I feel like at this point California considers water carcinogenic now.