Zeiss Purecoat - is it just me?

**opticianbart** · 08-27-2010, 08:57 AM

So I don't think I've ever noticed this happening with Teflon AR (which is what we tend to use), but we've tried a couple Zeiss Purecoat lenses at the urging of our rep. Basically what happens is this, we heat the frame up to make an adjustment, or to insert, or remove a lens and the lens coating crazes, or something like it. I feel like the coating is much more susceptible to heat than other AR's I've delt with. I'm wondering if anyone else has noticed this, or is my mind going? (I have been told I've been "twitching" lately....)

**eyeguy21** · 08-27-2010, 09:05 AM

You know I noticed it too. I've only had it happen once with newer AR's but never with Teflon. The generation before Teflon for us was Allure and that one crazed badly if you didn't pop out the lenses to heat it. I'm wondering what's different about the Teflon compared to the purecoats etc too.

**kcount** · 08-27-2010, 12:28 PM

I haven't seen any crazing issues but my pair of Purecoats have scratched up terribly.

**AngeHamm** · 08-27-2010, 01:13 PM

Several months ago, we had a span of several weeks where it seemed like every other stock poly Avance lens crazed. Aren't these expensive fancy "supercote" lenses supposed to be more resistant to damage, not more prone to it?

**EdgeOptical** · 08-27-2010, 01:49 PM

i havent found any crazing issues, but it does seem more prone to scratching.

i started using teflon elite (the teflon branded version of the same coating) to see if that makes a difference (i doubt it will)

and using alot of hoya ex3 now too.

**kcount** · 08-27-2010, 03:51 PM

I'm trying Tzavorite from Opticoat next, their Illusion HD has been impressive to date and the price is right.

**sharpstick777** · 08-30-2010, 02:08 PM

No problems with Purecoat here... except it doesn't come finished.

**cocoisland58** · 08-31-2010, 04:54 AM

Just started using teflon so can't comment on Zeiss coatings yet but I would never heat a zyl frame with AR lenses without removing the lenses first. Better safe than sorry.

**Fezz** · 08-31-2010, 06:44 AM

Originally Posted by cocoisland58

Just started using teflon so can't comment on Zeiss coatings yet but I would never heat a zyl frame with AR lenses without removing the lenses first. Better safe than sorry.

Don't you have to heat the frame to remove the lenses?

**eyeguy21** · 08-31-2010, 03:50 PM

Heat's for woosies. I just usually stare at the frame until the lens pops loose out of fear.

**m0002a** · 03-12-2014, 10:39 AM

Anyone have an updated opinion on Zeiss Purecoat? I never had a problem with Zeiss Carat Advantage, and Zeiss claims that Purecoat is more durable than Carat Advantage and will last the life of the lens, so I am a little concerned about some of the comments above.

**NCspecs** · 03-12-2014, 11:18 AM

I just don't get the same durability from Purecoat that I do with Avance and EX3. I love the Individual but I hesitate to fit it unless I stress to the patient the delicacy of the lens and then seem to accept/understand. I don't get a lot of crazing, rather I get a lot of perplexed patients coming back after 6 months for scratch warranty replacement swearing that they do nothing different with the care or cleaning of the lenses. I would write off the extreme scratching as carelessness if I didn't have so many dissatisfied patients!

All in all, its very frustrating because I really love to use Zeiss lenses when applicable. I hope they get this loose chink in the armor figured out.

**higgy** · 03-12-2014, 02:14 PM

Heat, bending, and improper deblocking are AR's worst enemies. I pop out all lenses cold and without bending. And when deblocking AR coated lenses you need to twist the block and not pop it off. Inserting you can heat all you want without ruining anything.

**ak47** · 03-12-2014, 03:15 PM

No, it is not just you!

Having said that, a simple thing to help when heating any glasses (especially a pair you are afraid to remove lenses from) is to wrap a lens cloth or two around each lens before putting in the hot air frame warmer. You don't want to stress the lenses with extreme heat changes.

**Uilleann** · 03-12-2014, 04:29 PM

Our experience is the same. Coupled with the fact that Zeiss is by far the most expensive lens lab we've ever used - even after their discounts off regular list. The optics might be excellent, but the AR failure issue is too large an elephant in the room to glance over.

**standarduck** · 03-13-2014, 01:27 PM

I was taught not to heat AR coated lenses - is that not something that is relevant any more?

**Chris Ryser** · 03-13-2014, 01:34 PM

When heating a frame the plastic gets soft.............as the lenses are also som plastic they also get softer, the AR coatings main igredient is CI02 which is glass, that does not get soft at that tremperature it will not flex along with the rest and craze...............kind of natural and logic

**standarduck** · 03-13-2014, 02:06 PM

Yes, as I thought. So the question is, why is this being ignored?

AR coats are always claiming to be harder ander harder (and harder, year on year). They must lose some flexibility in this process. This would make them more suseptible to crazing.

**NCspecs** · 03-13-2014, 04:06 PM

Originally Posted by standarduck

Yes, as I thought. So the question is, why is this being ignored?

AR coats are always claiming to be harder ander harder (and harder, year on year). They must lose some flexibility in this process. This would make them more suseptible to crazing.

A/Rs will definely lose flexability with a harder coat, therefore making it sensitive to temperature changes- I don't think anyone is ignoring the logic, I just don't think that explanation is especially pertinent to the question/complaint...at least for many of us seasoned ECPs in regard to this particular product.

I could be wrong in my assumption- sometimes I tend to assume that everyone thinks the same way I do!! :)

**m0002a** · 03-13-2014, 08:59 PM

Originally Posted by standarduck

Yes, as I thought. So the question is, why is this being ignored?

AR coats are always claiming to be harder ander harder (and harder, year on year). They must lose some flexibility in this process. This would make them more suseptible to crazing.

But it seems to me that some in this thread are saying that Purecoat scratches more easily than other high end AR's, and others are saying it crazes more often. I could understand that an AR could be so hard that it is not as flexible and therefore crazes more than others (especially when heated), but shouldn't such a harder AR be more scratch-resistant?

**Uilleann** · 03-14-2014, 09:46 AM

No real problems with crazing for us or our patients - but the scratch resistance is all but non-existent it seems. That is what most patients will key into before anything else, and is sadly one of the the main reasons we don't use much Zeiss at all these days.