Selling standard plastic- do you much?

[Ejmaxie]

Any time I have the combo of: pt over 18, full frame, rx under -2.00, I suggest cr39. I do tell them there are thinner options, and for anyone who needs impact, it's an obvious no. I would much rather have a patient in a/r than a high index material. Just yesterday I had a guy with a -3.50 in a 54 eye frame do cr39 because he wanted xtra-active TRN and it was the only available material. I myself have a huge sun frame with cr39 and I'm a -3.75, with drivewear. The edges are pretty thick, but I don't care.

Isn't that funny, in the store where I'm in, can only get Xtra-Active in airwear. What's up with that?

[AustinEyewear]

CR-39 is typically not the best lens when all parameters are considered. It is, however, an alternative when budget is in question. But for all you angels that care so much about your patients budget, why don't you just send them to over to Wally World.

[Robert_S]

First of all, hi everyone. This is my first post here.

I was surprised to read this discussion, in all honesty, since I thought we had reached a consensus that for every material there was a scenario in which it will function best and as such CR39 has its place. I'm obviously mistaken... but I can't understand why anyone would rarely sell CR39, given the fact that the majority of prescriptions we dispense with are reasonably low.

However, with regards to the couple of posters who use CR39 in supra frames, I personally don't think you're giving the patient either the best solution or the best value for money when you do that.

Not to bring the thread off topic, but Hoya has recently stopped producing lenses in 1.7, which for me is extremely disapponting, although I can certainly understand their need to do so since, let's face it, the majority of people dispensing eyewear (in the UK at least) know absolutely nothing about materials except that some are 'thinner'. I felt that 1.7 had some great properties.

[Happylady]

No more 1.7?

[RT]

Hoya 1.70 production was interrupted by the floods in Thailand last fall, but it has recently resumed.

[AustinEyewear]

The reason why some people support CR39 so much...... (hint: you get what you pay for)

Wholesale prices removed

[Robert_S]

Hoya 1.70 production was interrupted by the floods in Thailand last fall, but it has recently resumed.

I'm in the UK....

We've been told 1.7 is NEVER coming back; it's been removed from all the product catalogues and price lists. They were already phasing it out before the floods.

[MakeOptics]

I charge a small amount for poly over CR and poly is best in lower powers as its effects on clarity become negligable in low powers, but the impact resistance stays supurb. If the power reaches a point where clarity becomes an issue, the trivex is a good choice and then 1.6.

Opticians are sales people, how is this still being argued almost 100+ years later. The professionals created a prpgram that they introduced in school called a DO at firts which is now an OD almost 100 years later.

Opticians stayed inside jewellers shops and peddled from carts. Now they have upgraded to store fronts and ecommerce.

[AngeHamm]

Having observed a marked decrease in the quality and durability of polycarbonate lenses recently, my office is dispensing many more 1.50 and 1.60 plastic lenses in the past year.

For pretty much anyone under +/-2.00 and not in a grooved or drilled lens, CR39 is an ideal material: inexpensive, durable, available in a huge variety of styles, and the best optics next to glass. We're using poly for kids, safety, and low-powered grooved and drilled lenses. When the powers get in the +3.00/-4.00 area, we start talking to patients about 1.60.

Bravo to the brave, educated souls who are sticking to their guns with CR-39 in despite of the temptation to upgrade everything. It's still a superb and versatile material, and all many patients need. If I wasn't a -9.00 I'd be wearing it myself.

[Steve Machol]

As per the forum rules please do not post wholesale prices in a public forum. You also cannot advertise or promote your business here. To do that you must purchase a subscription to OptiBoard and post in the Marketplace forum. Thank you.

The reason why some people support CR39 so much...... (hint: you get what you pay for)

[Uilleann]

...cause who needs UV protection anyway! CR is cheap and that's all that matters!

[AngeHamm]

...cause who needs UV protection anyway! CR is cheap and that's all that matters!

Come on now. No one said anything like that, my friend. Besides, most of my patients are wearing some combination of Transitions, Crizal AR, and/or second pair polarized suns anyway...

[Wes]

...cause who needs UV protection anyway! CR is cheap and that's all that matters!

UV dip is cheap too.

[MakeOptics]

UV dip is cheap too.

The labor to apply it is not. I get poly for similar pricing that I get CR-39 so the point of price is really moot in my scenario. I find it hilarious that while people call poly inferior they continue to use the term "upgrade" when they talk about using it instead of CR-39. I think subliminally they would love to sell more poly, but they aren't as well suited in the sales arena.

[Java99]

The labor to apply it is not. I get poly for similar pricing that I get CR-39 so the point of price is really moot in my scenario. I find it hilarious that while people call poly inferior they continue to use the term "upgrade" when they talk about using it instead of CR-39. I think subliminally they would love to sell more poly, but they aren't as well suited in the sales arena.

Price upgrade rather than quality upgrade. And it takes about ten seconds to put the lenses in a clamp and plunk them in the UV.

[optilady1]

Back when I worked at the LC, they actually had little to no price difference, because they didn't want to sell it. I don't know why either, because the generators were way more likely to create a wave than cr39

[MakeOptics]

Price upgrade rather than quality upgrade. And it takes about ten seconds to put the lenses in a clamp and plunk them in the UV.

It only takes me about 5 minutes once to determine that a lens fit at 12mm vertex distance won't exceed Mo Jalies threshold for TCA in a polycarbonate lens until the power reaches a +/-2.00D, setting side the UV factor the patient will not notice any appreciable difference in quality of optics of course this is assuming a SV lens center properly. What the patient will gain is greater impact resistance. Also the poly lenses that I use are aspheric, I do wish that CR was available in an aspheric option, but unfortunately they are not.

So the Poly lens at or below a 2.00 D is going to exhibit all the positive attributes of the material with none of the drawbacks. I Think the majority of fitters are fitting poly wrong, you all fit it when the power gets high, but that's when the issues start to become more apparent. I fit it in SV and low powers, anything PAL, Multi, or High Power gets trivex or 1.60. Enough of the lessons, keep fitting the way you want, ignore the math, and call me a salesman but my clients get the best of me and my mind products are only the bullets in my guns.

[I-Care]

Completely agree! I prefer Trivex but will us CR39 for a groove job. I HATE POLY! Lots of patients have trouble with clarity wearing poly- I can change ONLY the material to CR39 and solve many visual problems.

[I-Care]

My thoughts exactly!

[AngeHamm]

So the Poly lens at or below a 2.00 D is going to exhibit all the positive attributes of the material with none of the drawbacks.

I put some patients under +/-2.00 in poly as well, but there are definitely drawbacks over CR39 at those powers. My engineer and photographer patients notice the chromatic aberration. Modern poly has an increased tendency to split and crack in the corners and the top of the frame when grooved. And its thinness and flexibility makes it much more prone to crazing than more rigid plastics.

[edKENdance]

Here's my poly moment from today. A lens with a crack running from top to bottom. Wherever she got them from had polished the lenses too. Other than that the frame was in mint condition as they were only a week old.

[mdeimler]

The problem with the low power poly is that they are thin. When these thin lenses are improperly edged too large, they flex and eventually crack. Too many lab techs do not know how to properly edge lenses.

[doctorjmjb]

It only takes me about 5 minutes once to determine that a lens fit at 12mm vertex distance won't exceed Mo Jalies threshold for TCA in a polycarbonate lens until the power reaches a +/-2.00D, setting side the UV factor the patient will not notice any appreciable difference in quality of optics of course this is assuming a SV lens center properly. What the patient will gain is greater impact resistance. Also the poly lenses that I use are aspheric, I do wish that CR was available in an aspheric option, but unfortunately they are not.

We use aspheric CR-39 all the time, the plus lenses really look sweet! (with the reduced magnification and the flatter profile) Bottom line with CR-39, you can't get any better optical clarity except for glass. And, whatever you can do to poly to make it more scratch resistant, CR-39 is better (provided that the same coatings are used.)

[Robert_S]

How ironic that the people criticising the quality of CR39 are instead advocating poly, which is probably the lowest quality material of all and should be avoided at all costs.

[Robert_S]

And I don't know why anyone brought up asphericity in the first place.