Why the AR Coat Peels Off

**george dimitrov** · 04-16-2009, 01:30 AM

Dear Friends,

I have a terrible problem with AR coat stabilility on stock lenses that I order from China. The coating scratches very easy durring the centering by the lensmeter. Very often the coat falls at concave part. In my country here is no testing lab that may do any quality tests.
The main problem is in that every producer from far east promis the best but, the result is .....:angry:

Please, help.

**cocoisland58** · 04-16-2009, 06:05 AM

I really can't bring myself to state the obvious.

**Happylady** · 04-16-2009, 09:35 PM

Maybe not buy unbranded lenses with AR from China? They sound like junk. If they do this for you, I am sure they aren't holding up well for your patients/customers either.

**IC-UC** · 04-16-2009, 11:25 PM

There are many stock lens manufacturers in China who do work for the larger companies.
Perhpas you need to go through one of the bigger lens companies to get better quality lenses from China, as doing it yourself without any proper testing lab, will only result in problems?

Why dont you do your own in-house testing? Some basic steps and you can do rudementary testing of quality. Obviously you wont be able to replicate what COLTS does, but some basic tests will telll you what may go wrong.

Send me a message if you need some information or help.

**Golfnorth** · 04-17-2009, 05:37 AM

Originally Posted by cocoisland58

I really can't bring myself to state the obvious.

lol

**Specs** · 04-17-2009, 12:05 PM

ic-uc, what kind of in-house testing can be done to show the difference in qualities of A/R

**AdmiralKnight** · 04-17-2009, 01:10 PM

Well, a good rule of thumb would be, if the lens scratches from putting it in the lensmeter, chances are it's not a good lens.

**cityconnection** · 04-18-2009, 10:06 AM

If it is scratching that easily that means when they are cleaning the lenses it will scratch too. My opinion would be to change lenses and before buying stock, order a few pairs to test them out. Even if it is more expensive for the few pairs, youll be better off in the long run.

But stay away from inferior products if you plan to be business in the long run.

**Chris Ryser** · 04-19-2009, 02:21 AM

IC UC is right, it is easy to do basic test's..........................

Also do not forget that the brand name stock lenses come from the same corner of the word and you use them without question. Maybe Goerge Dimitrov in Bulgaria just caught a bad egg or looked for the cheapest among the cheap. :finger:

**IC-UC** · 04-21-2009, 12:44 AM

A basic salt water boil test will determine the quality of a AR coated lens. The solution is around 5% sodium chloride brought to the boil. You then put the lenses in (with a BPI tint lens holder or similar) ad leave it for 2 minutes. Then remove from salt water and put in cold water rinse for a minute. Check the lens for any peeling or crazing and determine a scale. Typically 1 - 5 is used (1 bad, 5 excellent)
Do the same test 10 times hich replicates the natural use of a lens over time. Poly should fare much better than CR39, but it does depend on the hardcoat and AR coat interaction.

Typically with a Poly spin coated lens with a decent AR, you should have a rating of 4-5.
On CR39 with a spin coat and AR coat, you would most likely get a 3, but this is more due to the thermal expansion of the CR material, so the rating is not to be looked at alone. Abrasion testing, adhesion testing and heat tetsing all together count for the quality on lenses.

But doing the salt water boil test is one quick easy way to check your quality. But by no means the only way, there are other factors that nee to be taken into account. It also depends on the country and what legislation relates to lenses ther, also bear in mind the VOC (voice of customer) and VOB (voice of business).

BTW - George Dimitrov, I could not reply to your message as your settings were not set up, so hope this reply gives you some idea.

**chip anderson** · 04-21-2009, 09:36 AM

Welcome to the many benefits of communisim/socialisim where very soon we will all be made equal.
Would have thought someone from Hungary would have had enough of this under Soviet Rule to learn not to deal with communists after getting out from under.

Chip

**cityconnection** · 04-21-2009, 01:50 PM

Originally Posted by IC-UC

A basic salt water boil test will determine the quality of a AR coated lens. The solution is around 5% sodium chloride brought to the boil. You then put the lenses in (with a BPI tint lens holder or similar) ad leave it for 2 minutes. Then remove from salt water and put in cold water rinse for a minute. Check the lens for any peeling or crazing and determine a scale. Typically 1 - 5 is used (1 bad, 5 excellent)
Do the same test 10 times hich replicates the natural use of a lens over time. Poly should fare much better than CR39, but it does depend on the hardcoat and AR coat interaction.

Typically with a Poly spin coated lens with a decent AR, you should have a rating of 4-5.
On CR39 with a spin coat and AR coat, you would most likely get a 3, but this is more due to the thermal expansion of the CR material, so the rating is not to be looked at alone. Abrasion testing, adhesion testing and heat tetsing all together count for the quality on lenses.

But doing the salt water boil test is one quick easy way to check your quality. But by no means the only way, there are other factors that nee to be taken into account. It also depends on the country and what legislation relates to lenses ther, also bear in mind the VOC (voice of customer) and VOB (voice of business).

BTW - George Dimitrov, I could not reply to your message as your settings were not set up, so hope this reply gives you some idea.

That is VERY helpful information. This way I can test lenses when companies give us samples. Until now I have just been looking, observing, and cutting them to see how hard/strong they are...

**george dimitrov** · 04-22-2009, 01:32 AM

Dear All,

Thank you so much about replies.
Do someone known where the bigger companies order their stock lenses?
Everybody declare that, the names in lens market also order in Far East, but till now nobody pointed from where.Is it just a rumor? Is it their own factories or there is also independent producers that offers reliable quality on reasonable prices.The practice with samples is O.K., but how could be sure that the received quality will be the same as the preceding samples. They could send one as a sample and totally deferent as a forwarding order.
I am not that kind of trader that just want to buy at the lowest possible price.
The hard point is in that I HAVE NEVER MET A PRODUCER WHO OFFERS THIRD/SECOND AND FIRST QUALITY. Usual they declare that their quality is always the first, but in case of complain they are ready to replace the goods. But the complain used to happened after some months. And the results is worst.
The opticians on my market always need something that is cheap, then they exist extra discount and so on. I could not reply on that request with European production because of the price, but the amazing is in that the products with reasonable price from European producers are not made here, but in Far East...!

**tonyl** · 04-22-2009, 06:56 AM

You could look at http://www.setolens.com/

or http://www.polycore.com/

These are not premium lenses but hopefully reliable.

These seem to be bigger suppliers. No guarantee of quality to use the bigger ones, but you would think that if they accidentally produce a dud lot then they would sell it under a different name rather than put their own name on it.

All of the big companie like Zeiss and Essilor make most of their stock lenses in Asia.

In fact one of the directors of SOLA once told me that the only place in the world where they can make 1.74 material is in China because it is an extremely toxic manufacturing process. Even the Indian authorities would not allow them to make 1.74 there.

**IC-UC** · 04-23-2009, 08:21 PM

You can try the following company. They are based in Singapore, which may or may not make them cheaper than your current suppliers.

http://www.osa.com.sg/

**tonyl** · 04-23-2009, 10:42 PM

Wow. I didn't realise that OSA was so big in Singapore.

We get stock lenses from the Australian OSA, but here it is just a small branch of Essilor. They tell us that many of the OSA lenses are identical to Essilor lenses.

Can you deal direct with OSA Singapore? They appear to be a wholesale operation, not a manufacturer. Would it be cheaper?

**IC-UC** · 04-24-2009, 12:17 AM

We also get them through Essilor. Not sure if you can go direct, but there does not seem to be any reason why not.
It may make it cheaper going through Essilor with regard to freight and duty etc....but who knows, ask them for a quote.

**DocInChina** · 04-24-2009, 02:28 AM

Originally Posted by tonyl

In fact one of the directors of SOLA once told me that the only place in the world where they can make 1.74 material is in China because it is an extremely toxic manufacturing process. Even the Indian authorities would not allow them to make 1.74 there.

1.74 is made in Japan and Korea. It is not made in China.

**Trevor D** · 05-03-2009, 05:21 AM

Hey Tony and IC-UC,

http://www.osalens.com.au/

**ilanh** · 05-03-2009, 11:21 AM

This is indeed a big problem. I have seen and tested many lenses which come with house AR and they are always promised to be the best quality. Within a year the customers are back with horribly scuffed, scratched and generally delaminated AR's. I have found a few vendors, such as Kmars, whose AR seems to be of high quality even though it's low priced. I am now suitably suspicious of any low priced AR and am very reluctant to use anything that I don't have direct references of.

**For-Life** · 05-03-2009, 11:52 AM

Originally Posted by ilanh

This is indeed a big problem. I have seen and tested many lenses which come with house AR and they are always promised to be the best quality. Within a year the customers are back with horribly scuffed, scratched and generally delaminated AR's. I have found a few vendors, such as Kmars, whose AR seems to be of high quality even though it's low priced. I am now suitably suspicious of any low priced AR and am very reluctant to use anything that I don't have direct references of.

This is exactly why I am done playing the game with companies I do not know. This is why I refuse to sell anything but the premium ARs.

**jameselex** · 05-03-2009, 10:11 PM

Originally Posted by george dimitrov

Dear All,

Thank you so much about replies.
Do someone known where the bigger companies order their stock lenses?
Everybody declare that, the names in lens market also order in Far East, but till now nobody pointed from where.Is it just a rumor? Is it their own factories or there is also independent producers that offers reliable quality on reasonable prices.The practice with samples is O.K., but how could be sure that the received quality will be the same as the preceding samples. They could send one as a sample and totally deferent as a forwarding order.
I am not that kind of trader that just want to buy at the lowest possible price.
The hard point is in that I HAVE NEVER MET A PRODUCER WHO OFFERS THIRD/SECOND AND FIRST QUALITY. Usual they declare that their quality is always the first, but in case of complain they are ready to replace the goods. But the complain used to happened after some months. And the results is worst.
The opticians on my market always need something that is cheap, then they exist extra discount and so on. I could not reply on that request with European production because of the price, but the amazing is in that the products with reasonable price from European producers are not made here, but in Far East...!

While it is very hard to get the best quality except paying premium for big names( even some of the big name fails quite often, let's not get into that), but it is possible to get good A/R from China ( without peeling off in one year/ scratch from wear & tear), you got to be careful and not squezze them too much. let me know if I can help.