Justifying an A/R coat...

[EyeFitWell]

I've heard that studies indicate bullet lenses are the best, most affective, demo. I personally prefer using the one lens has AR, one lens does not mounted in a frame.
Which do you prefer? Do you show them anything at all?

[k12311997]

I've heard that studies indicate bullet lenses are the best, most affective, demo. I personally prefer using the one lens has AR, one lens does not mounted in a frame.
Which do you prefer? Do you show them anything at all?

someone stole our demo that just had AR in the center of a plano finished lens we have the mounted split AR demo what I find most effective is having the person look at me with my AR and then looking at themselves in the mirror with their glasses on.

[Fezz]

someone stole our demo that just had AR in the center of a plano finished lens we have the mounted split AR demo what I find most effective is having the person look at me with my AR and then looking at themselves in the mirror with their glasses on.

I might have an extra one laying around, Would you like one?

[tmorse]

LOL. I will never evvvvvvvvvver go back to glasses without AR. My mother got glasses for the first time with AR after a couple f decades of wearing glasses. She worried about the extra money so I shelled ou the monies for her and she loves them.

I had to take AR off one time. When the lady looked in the mirror she immediately freaked... she hadn't realized that she had so many 'age lines' under her eyes and they all showed.:cheers:

[k12311997]

I might have an extra one laying around, Would you like one?

Thanks for the offer that just might be the incentive to drive across the state and buy you a beer.

[For-Life]

I had to take AR off one time. When the lady looked in the mirror she immediately freaked... she hadn't realized that she had so many 'age lines' under her eyes and they all showed.:cheers:

Yes, you better be careful of the dreaded lines. That means you have to have a big, black plastic frame with tinted lenses and no AR.

Now no one will be able to tell she is aging behind the old, ugly glasses.

[Fezz]

Thanks for the offer that just might be the incentive to drive across the state and buy you a beer.

What the heck, for a beer..I would meet half way!;)

[motelska]

I found an old pair of glasses in my closet recently. It was the old Opyl 1028 from the early 80's. Believe or not, the rx is not that far off. But when I put them on I immediately noticed loads of reflections in my lenses from all the lights in the room. I never get that with my AR lenses.

I got my first pair of glasses with AR in 1986 and would never get a pair with out it. I remember being bothered by reflections. I see so much better with it.

I tell patients that it is like turning the light up a little in the room, they get more available light. This is particularly true with poly and high index lenses. I tell them it eliminates reflections, helps with night time driving, and makes the glasses look much better.

I had one patient that got their first pair of AR lenses. Same rx as her old glasses just this one had AR and she said "It's like looking thru HD"

[EyeFitWell]

I've used the High Def comparasion before.
Or, VCR vs. DVD. Actually, this works really well b/c some people say "they haven't noticed any problems" and I explain that we used to be impressed by a VHS video, now look at a DVD, you didn't know what you were missing!

[akeroptical]

The one misconception that I have dealt with is a particular company refering to A/R as a "No Glare" coating. When I was at that company patients would hear "No Glare" and assume it would reduce glare when veiwing other objects. I spent a good deal of time explaining that reflections on the surface of the lenses had nothing to do with the glare they see on on-coming windshields, street signs, ect. I would show them that polarized sunglasses had that affect but that A/R would improve the performance of the lenses by removing distracting "Reflections" from their lenses.

Its not a "no glare" coating, its an Anti-Reflective coating.

[sharon m./ aboc]

It just like when the customer comes in and says, "I bought the scratch proof lenses." Yeah...they aren't "scratch proof" they're scratch RESISTANT dumb a**!":bbg:

[LKahn]

A fairly large number of lens that are described as "scratch resistant" are not. Some firms are selling "slippery" as scratch resistant. Slippery is entirely different than abrasion resistant.

In industry at large scratch resistance is technically called abrasion resistance and is measured with a "Bayer Test". A Bayer test is performed with steel wool at a specific pressure for a specific number of strokes. Then the surface is examined for haze.

[For-Life]

A fairly large number of lens that are described as "scratch resistant" are not. Some firms are selling "slippery" as scratch resistant. Slippery is entirely different than abrasion resistant.

In industry at large scratch resistance is technically called abrasion resistance and is measured with a "Bayer Test". A Bayer test is performed with steel wool at a specific pressure for a specific number of strokes. Then the surface is examined for haze.

true, but then we have to question what causes scratching. If it is particles on the lens that are rubbed into it then maybe slippery will help.

The Alize is no more abrasive resistant than Crizal, but because it is much more slippery I bet you it will get less scratches under same use.

[LKahn]

That is an interesting supposition. But if that were true, a Teflon fry pan in your kitchen would not have the scratch problem that it does.

Slippery is an effective finish to protect against sticking, like in a fry pan. But, the pan still scratches. Slippery is desirable, it just is not abrasion resistance. They are different features.

Do a simple test. Say 10 strokes with "00" steel wool at an equal pressure. Look for the Haze. You can try this on any slippery coating. There will be abrasion. Try it on your Teflon fry pan. There will be abrasion.

The point is, "What many sell as scratch resistance is not".

true, but then we have to question what causes scratching. If it is particles on the lens that are rubbed into it then maybe slippery will help.

The Alize is no more abrasive resistant than Crizal, but because it is much more slippery I bet you it will get less scratches under same use.

[For-Life]

But then you question what is being scratched on the pan, the coating or the pan? Now it is the same with AR, but if the coating is that much more harder then the slipperness will not make it more or less abrasive. Therefore, using the same substance it would keep it more slippery and thus gain less scratches.

[LKahn]

We manufacturer both a hard coat and a scratch coat. Each are different. A hard coat provides extra strength in a penetration test (drop ball test) and some properties of adhesion for other layers such as AR.

The example I always use is steel. Steel is very hard (difficult to penetrate) but fairly easy to scratch unless you apply a scratch resistant coating. Think of the painted front quarter panel on your car. It has several layers of paint (similar to AR) The metal is hard, but easy to scratch.

The struggle I have with the optical industry is the willingness of many to tell the consumer they have a scratch resistant coating (when in fact it is not) and then complain when the consumer expects scratch resistance.

My view is the optical retail store should explain the AR coating needs to be treated respectfully and can scratch and say no more. But, many go further and make claims regarding scratch resistance which can not be substantiated.

But then you question what is being scratched on the pan, the coating or the pan? Now it is the same with AR, but if the coating is that much more harder then the slipperness will not make it more or less abrasive. Therefore, using the same substance it would keep it more slippery and thus gain less scratches.

[For-Life]

Okay, but is it fair to say that the quality, premium AR's tend to be as or more scratch resistant than the scratch resistant coatings on the market?

[HarryChiling]

The point is, "What many sell as scratch resistance is not".

Are you saying that a slippery coating has no effect?

A lens without any coating and a lens with a slippery coat will have the same amount of haze when subjected to the steel wool abrasion test?

[FCChemist]

We manufacturer both a hard coat and a scratch coat. Each are different.....

Larry, I also work for a company that manufactures hard coats (scratch resistant coatings, abrasion resistant coatings, or whatever you want to call them). Though there are many types and classes of abrasion resistant coatings, I've never seen anyone, other than you, distinguish a hard coat from a scratch coat. There are two primary classes of abrasion resistant coatings, thermal cure and radiation cure (e-beam or UV). Premium hard coats today, radiation or thermal cured, are often based on nanotechnology where the organic hard coats are filled with a metal oxide (SiO2, Al2O3, ZrO2, etc) less than <30 nm in size. These inorganic particles increase the abrasion resistance and modifies the refractive indices of hard coats. Other additives can be used for other properties, including, additives or monomers that increase the adhesion of the hard coat to an AR coating.

Claiming an article to be scratch resistant due to an applied hardcoat is not wrong nor misleading. It simply means that the plastic lens without the coating would be more prone to scratching from abrasion than with a hard coat. This is true for even the AR coating which is always applied on top of the hard coat. The scratch or abrasion resistance of the AR coating is dependant upon the underlying surface to which it is applied. An AR coating applied to bare polycarb it would be more prone to scratching then if applied to a hardcoat on polycarb.

[LKahn]

I 've open a can of worms.

1. Harry, slippery on its own is not scratch resistance. It is just slippery. The classic example is a non stick coating on a fry pan. It is slippery and still scratches fairly easily.

1. FCChemist, outside of the optical industry a hard coat and a scratch resistance coating are 2 distinctly different coatings. The hard coat applied to polycarbonate give the plastic substrate more penetration resistance for a drop ball test and the adhesion needed to sustain the AR coating. So I as ask you, What standard industrial measurement test do you use to test abrasion on the AR coating? One should be using a "Sward Hardness" test and a "Bayer" test. Call me directly I will explain. 407 898 2323

[Chris Ryser]

A fairly large number of lens that are described as "scratch resistant" are not. Some firms are selling "slippery" as scratch resistant. Slippery is entirely different than abrasion resistant.

In industry at large scratch resistance is technically called abrasion resistance and is measured with a "Bayer Test". A Bayer test is performed with steel wool at a specific pressure for a specific number of strokes. Then the surface is examined for haze.

SCRATCH RESISTANT TREATMENTS ON OPTICAL LENS SURFACES

Definition of a Hard Coat on optical lenses:
A layer of material that is harder than the basic material (substrate) . The hard coat material is chemically bonded to the substrate and its hardness is limited to the flexibility of the basic lens material. (crazing, delaminating)

Resulting effect on a Hard Coated lens:

As the applied layer is harder than the basic surface it has been established that with a Taber test, pencil test or a haze test (generally accepted testing methods) the added layer of harder material took longer to be damaged in those test’s than the basic material.

Definition of a Slick Coat:
This treatment consist of the application of a polysiloxane polymer or teflon layer on the substrate.
These materials do NOT provide a so called hard coat. (therefore conventional pencil and haze test’s are invalid and do not apply))

These products provide a very thin ULTRA SLICK surface. A surface treated with these materials will let objects slide off the surface instead of hooking on and scratching the surface. If an anti-stat agent is added to the material, the surface will not accept static charges and therefore dust will not cling to it and lenses stay clean much longer. As an other additional benefit anti-fog agents can also be added to speed up and dissipate fogging up of the surface.

Excert from: http://optochemicals.com/products/in...resist_gen.htm

[Chris Ryser]

I 've open a can of worms.

1. Harry, slippery on its own is not scratch resistance. It is just slippery. The classic example is a non stick coating on a fry pan. It is slippery and still scratches fairly easily.

1. FCChemist, outside of the optical industry a hard coat and a scratch resistance coating are 2 distinctly different coatings. The hard coat applied to polycarbonate give the plastic substrate more penetration resistance for a drop ball test and the adhesion needed to sustain the AR coating. So I as ask you, What standard industrial measurement test do you use to test abrasion on the AR coating? One should be using a "Sward Hardness" test and a "Bayer" test. Call me directly I will explain. 407 898 2323

Larry,............you are making some strong statements and you seem to want change the rules. Maybe you should read a few more books and articles on the subject that have been published since hard coating and scratch resistant treatments (2 totally different babies) came up in the late 1970s and early 1980s. :D

[HarryChiling]

I 've open a can of worms.

1. Harry, slippery on its own is not scratch resistance. It is just slippery. The classic example is a non stick coating on a fry pan. It is slippery and still scratches fairly easily.

1. FCChemist, outside of the optical industry a hard coat and a scratch resistance coating are 2 distinctly different coatings. The hard coat applied to polycarbonate give the plastic substrate more penetration resistance for a drop ball test and the adhesion needed to sustain the AR coating. So I as ask you, What standard industrial measurement test do you use to test abrasion on the AR coating? One should be using a "Sward Hardness" test and a "Bayer" test. Call me directly I will explain. 407 898 2323

The question was does the slick coat have any effect on the haze over a non slick coated lens? If you are saying it is not a scratch resistant coating and the definition of a scratch resistant coating is to resist scratches, then if their is less scratching, then you have a scratch resistant coating. Support your conclusion with data.

Maybe you should read a few more books and articles on the subject that have been published since hard coating and scratch resistant treatments (2 totally different babies) came up in the late 1970s and early 1980s. :D

Care to name a few, books and articles?

[LKahn]

Chris

As I said it's a can of worms I have opened up

I totally agree with your statement below. Hard coating and scratch resistant treatments (2 totally different babies) My issue is with people that describe them as the same. I have no issue with slippery coatings. But a slippery coating is not a scratch coating. Each provides a different function.

Larry,............you are making some strong statements and you seem to want change the rules. Maybe you should read a few more books and articles on the subject that have been published since hard coating and scratch resistant treatments (2 totally different babies) came up in the late 1970s and early 1980s. :D

[LKahn]

Harry

Slippery does not equal scratch resistance. Lookup the definition of each word. They are very different. You are making an assumption that if a surface is slippery you most likely would have less abrasion. This may or may not be true.

On that basis, spray a fine layer of oil or water on a surface. It is slippery and yet would do nothing to prevent abrasion from steel wool. See my point. The real point I am trying to make is, scratch resistant coatings would better be described as a "surface coating" that make a surface (AR) more durable. A great deal of the frustration would be eliminated on the part of optical retail stores it were better described.

The question was does the slick coat have any effect on the haze over a non slick coated lens? If you are saying it is not a scratch resistant coating and the definition of a scratch resistant coating is to resist scratches, then if their is less scratching, then you have a scratch resistant coating. Support your conclusion with data.



Care to name a few, books and articles?