I've never seen such a bunch of hooey...

[drk]

The "damage from the computer screen" is the worst part of the lie that needs to be once and for all killed dead. And that is what 99% of the inquiries come from. As for the AR style lenses [Prevencia, Recharge, et al] they do more than a tint, in that they all ADD large amounts of reflection in the blue/purple band. The very antithesis of what an AR lens is designed to do. So why bother? Not being arrogant here - genuinely why? If you want a tint, get a tint. Your AR stack quality will suffer greatly of course, but that's just the way of things with porous, tintable lens stock. Of course, a light tint negates the increased transmittance of AR anyway, so we're back to square one again regardless. Feel free to slap that devil's advocate label firmly on my forehead Doc. :)

I'm glad this thread was resurrected because I need to digest the good stuff in this post!

1. You're saying that...a.) if you're putting AR on a lens, you put it on a lens that isn't "porous"? This is new for me. So...if a lab is doing AR do they choose certain lens types that cannot easily be tinted?

2. You are right, Uilleann, about the incorrect conflation I was having about AR and blue-reflecting lenses. While I would suppose they are similar in some ways, the better analogy I should use is a mirror coating. Right? Blue light lenses are like teeny-weenie mirror coats like on sunglasses.

3. But do they blue-coat the back side, too? (My blue-blocker Zeiss butter-vision specials DO look blue on the back...) That would seem counter-productive. It would be better for a standard AR on the back side, right?

4. Re: tinting and standard AR. Can we correctly separate two functions of AR coatings? Function 1: block surface reflections. Function 2: increase light transmittance. I know that destructive interference of the reflected light causes an automatic increase in light transmittance..."that destroyed reflection has to go somewhere". But if the lens is tinted, wouldn't it also allow anti-reflectance to occur? The tint would act as a "light sink", right?

So, my presumed conclusion is that you CAN separate the functions of AR.

[drk]

For the record, I would say that I don't think of BOTH anti-reflection functions very regularly, just the "hey, your lenses will look invisible" aspect. And we all talk about night driving and AR vis-a-vis point light sources and point-spread functions, but I know I neglect the aspect of it being like a "negative tint"...it INCREASES the light transmittance (in some cases by a non-negligible 5%-ish, on, say, polycarb) so they "see better in the dark".

What a sales pitch! My AR sales are going up a non-negligible 5%-ish on Monday!!!!

[lensmanmd]

That sound you’re hearing is corn popping, and the ice stirring for my whiskey sour.
Propping up my feet and getting comfy for this upcoming show.

[AngeHamm]

3. But do they blue-coat the back side, too? (My blue-blocker Zeiss butter-vision specials DO look blue on the back...) That would seem counter-productive. It would be better for a standard AR on the back side, right?

Zeiss AR lenses have a blue reflex color, so their non-HEV backside layer will look blue, just not as mirror-blue as the front.

[drk]

To blow my mind further, I was inspecting a job this a.m. that was a backside AR on a gray polar poly. And from the front, it looked like it had AR reflectance residual color. So, can I be seeing the forward-facing "inside" of the backside AR coating?

[Uilleann]

To blow my mind further, I was inspecting a job this a.m. that was a backside AR on a gray polar poly. And from the front, it looked like it had AR reflectance residual color. So, can I be seeing the forward-facing "inside" of the backside AR coating?

Possibly? I think I know what you're referring to. Typically, I don't see this at all on "package" type lenses, such as Xperio stuff, or Maui Jim as examples. But the parted out work, like iCoat, etc that do mirrors in one lab, and backside ARs in another. Not sure if it's a substrate matching thing, or poor primer coats or what?

[NAICITPO]

To blow my mind further, I was inspecting a job this a.m. that was a backside AR on a gray polar poly. And from the front, it looked like it had AR reflectance residual color. So, can I be seeing the forward-facing "inside" of the backside AR coating?

Possibly? I think I know what you're referring to. Typically, I don't see this at all on "package" type lenses, such as Xperio stuff, or Maui Jim as examples. But the parted out work, like iCoat, etc that do mirrors in one lab, and backside ARs in another. Not sure if it's a substrate matching thing, or poor primer coats or what?

Yes, I know exactly what this looks like too. I always wondered if the lab messed up and put AR on the front of the lens as well? It was really only noticeable when someone new to our office put a premium regular AR on the polar suns instead of Xperio UV. Like Uilleann said I have never seen it on Oakley, Rayban, Maui Jim, or any Xperio UV jobs.

[drk]

I'll try to remember Xperio UV for sunglasses.

[NAICITPO]

Possibly? I think I know what you're referring to. Typically, I don't see this at all on "package" type lenses, such as Xperio stuff, or Maui Jim as examples. But the parted out work, like iCoat, etc that do mirrors in one lab, and backside ARs in another. Not sure if it's a substrate matching thing, or poor primer coats or what?

[Lensman11]

If you mirror coat in one machine and backside coat in another it will have no Ill effect on the end product. I can’t understand why anyone would do that as it is lot more work and more chance for breakage either by having to rerack the lenses or moving the sectors to another machine. All the branded coatings are all done the same way they might be more durable but the reflectance is not visually different than low cost non branded coating. I am talking about the AR stack not the hard coats.

[Prentice Pro 9000]

I've heard trivex naturally blocks the higher end blue light. We sell a ton of trivex.

[Kwill212]

I've heard trivex naturally blocks the higher end blue light. We sell a ton of trivex.

"heard" where? Because I heard Drk likes ketchup on his spaghetti instead of marinara. Is it true? He hasn't denied it yet...

[Prentice Pro 9000]

"heard" where? Because I heard Drk likes ketchup on his spaghetti instead of marinara. Is it true? He hasn't denied it yet...

Oh man they say it at my current job. I work with career opticians that really know their stuff so it might be true. I don't know.

[drk]

Zeiss AR lenses have a blue reflex color, so their non-HEV backside layer will look blue, just not as mirror-blue as the front.

Yes, excellent!

[drk]

I think this, Prentice Pro 9000 Robot Optician:

If something blocks blue light, which is VISIBLE LIGHT (right?) then you're going to be able to SEE the subtracted effect.

That is, on a blue-blocking lens, it's going to look tan or brown or yellow or something, certainly from the back-side view.

And Trivex is not like that.

I think the guys you work with are going to send you out to look for a box of optical centers, next. You should strike first.

[Uilleann]

I think this, Prentice Pro 9000 Robot Optician:

If something blocks blue light, which is VISIBLE LIGHT (right?) then you're going to be able to SEE the subtracted effect.

That is, on a blue-blocking lens, it's going to look tan or brown or yellow or something, certainly from the back-side view.

And Trivex is not like that.

I think the guys you work with are going to send you out to look for a box of optical centers, next. You should strike first.

This x 1000.

[DanLiv]

Originally Posted by Uilleann: If you want a tint, get a tint. Your AR stack quality will suffer greatly of course, but that's just the way of things with porous, tintable lens stock.
1. You're saying that if you're putting AR on a lens, you put it on a lens that isn't "porous"? This is new for me. So...if a lab is doing AR do they choose certain lens types that cannot easily be tinted?

A quality AR stack like Uilleann is talking about will chemically strip and clean the lens and then apply a substrate-matched dip hardcoat first, which is non-porous and not tintable, and then the rest of the AR stack applied to that for maximum durability and adhesion. Crizal, Duravision, EX3 all use this process. In principle one can tint a porous substrate (CR39 or high index) first, then go through the process, but that stipping and coating will alter the tint so you get unpredictable results. Also many labs will not do this at all because the tint leeches out of the lens and contaminates their dip coating bath so they have to switch it out. The alternative then is to tint a porous lens and then apply a lower quality AR directly to the tinted substrate. Or even worse, tint poly which has been factory coated with a tintable layer (poly itself is not tintable) and then AR that, but the AR is only as durable as the underlying factory coating, which ain't great. That's the quality compromise of tinting.

3. But do they blue-coat the back side, too? (My blue-blocker Zeiss butter-vision specials DO look blue on the back...) That would seem counter-productive. It would be better for a standard AR on the back side, right?

Yes, proper blue filtering AR should be frontside only with regular backside, otherwise the backside is just bonuncing blue light into the eye. Counter-productive as you said. Ideally the backside AR is one with reduced UV reflectance too.

4. Re: tinting and standard AR. Can we correctly separate two functions of AR coatings? Function 1: block surface reflections. Function 2: increase light transmittance. But if the lens is tinted, wouldn't it also allow anti-reflectance to occur? The tint would act as a "light sink", right?

I have no science, but I think not. Reflectance occurs at the lens surface, destructive interference occurs only if the AR stack is the first surface light interacts with (notice AR does not work when smudges on the lens surface interact with light first). The reflectance will occur before the light reaches the tint. The tint would act a a light sink, absorbing some of the already reduced light that was not reflected at the surface.

[drk]

Dan Liv, thanks.

1. I do recall that a bunch of lens surface improvement is needed to put on a solid AR coating. Didn't know that a pre-tint makes the good AR process messy and unreliable.

2. Didn't know that there was an alternative "inferior" AR method available to deal with tinted lens surfaces.

The conclusion is, therefore, that a.) putting backside AR on a lab-tinted sunglass lens is a problem, but probably it's also true that b.) there is a product designed to deliver an AR-friendly tinted lens...doesn't essilor have those? And in poly? Sure, you can't order orange or pink, but you get gray, brown, and purple, I think. Am I right? Is this it (but it's polar)? https://www.essilorusa.com/products/...zed-sunglasses

NOT THAT WE DO MUCH BACKSIDE AR ANYWAY!

3. I guess this "lab tint + AR = inferior durability" bugaboo would put the kibosh on, say, a naiively-designed approach to have a "D-I-Y blueblocker" product. Say, I order a CR39 lens with a 10% brown tint and put traditional AR on it. It would work scientifically, but it would be an inferior-durability AR lens. Not that there's a big deal with that, I'm guessing, but...

[drk]

Of course, a light tint negates the increased transmittance of AR anyway, so we're back to square one again regardless. Feel free to slap that devil's advocate label firmly on my forehead Doc. :)

When Uillean says this, I took it to mean that he's confounded by those who--when adding an AR coating to a tinted lens--would be doing something counter-productive. He's saying, I think, that "Hey, you want AR coating to INCREASE the light transmission, dummy! Why block it with a tint?" No argument, there.

But I guess I was wondering if he's throwing out the baby with the tint water? Setting aside the AR quality issue and the reduced light transmission of the lens from the tint (a feature, not a bug, in the case of D-I-Y computer glasses) isn't AR still effective in blocking reflections on a tinted computer lens? So the AR has some useful purpose in that scenario.

[drk]

And Dan Liv, forgive please, because I not say "uncoated tinted lens is inherently anti-reflectant--no AR needed!" I no speak good English some time.

[Uilleann]

When Uillean says this, I took it to mean that he's confounded by those who--when adding an AR coating to a tinted lens--would be doing something counter-productive. He's saying, I think, that "Hey, you want AR coating to INCREASE the light transmission, dummy! Why block it with a tint?" No argument, there.

But I guess I was wondering if he's throwing out the baby with the tint water? Setting aside the AR quality issue and the reduced light transmission of the lens from the tint (a feature, not a bug, in the case of D-I-Y computer glasses) isn't AR still effective in blocking reflections on a tinted lens? So the AR has some useful purpose in that scenario.

Why tint a lens to reduce transmittance, when the buttons on your monitor, or your settings with a few mouse clicks will do FAR more - and for free? If your screen is THAT bright, simply turn the damn thing down. No need for a lens with all the colored grace of dirty toilet bowl water. :) As for AR, yes doc, you're correct. No benefit to counterproductive lens features, and reduced surface durability - which is why we don't do it.

[drk]

Because....usually we do it this way with the princess-and-the-pea-on-the-CRT*: +0.50 DS over distance refraction, plus AR coating.

But now, people are all "oooh, I want no blue" and I can

1. simply poo-poo
2. go blue
3. do a little AR with an ambient-lighting tint zippity-do.

After this fine thread, I'm going to stop #3 because of the AR durability loss on a tinted lens (although I'm sure that's not an absolute no-no.) I'll just say "OK" if they want a blue light mirror (and that's what I'm calling it, now!) but I won't be bringing it up unless they want it (and marketing seems to be working on them). If they ask my opinion, I'll tell them I don't think it matters.


*Princess-and-the-pea-on-the-CRT syndrome is for emmetropic non-presbyopes with normal binocular and accommodative function that simply report asthenopia or fatigue. It's also probably dryness related, too. You all get these types. But (as is the rage in the lens manufacturing world) there's a reasonably successful (if not placebo) solution with the low plus power lenses. I actually do think there's a positive response to a #1 density neutral or warm tint, but not everyone thinks it's "cool-looking" enough. That's where the blue light lens can be a help, as long as you don't represent blue light as a hazard; it's just a cool-light-wavelenght subtractor, with (as I have now learned) a nice back-surface AR. Nothing wrong with using it. The upcharge for blue-mirror over AR is about the cost of a traditional dye, as well. Plus you don't have to worry about tintable substrates or lower-quality AR, as I've learned.

[DanLiv]

The conclusion is, therefore, that a.) putting backside AR on a lab-tinted sunglass lens is a problem, but probably it's also true that b.) there is a product designed to deliver an AR-friendly tinted lens...doesn't essilor have those? And in poly? Sure, you can't order orange or pink, but you get gray, brown, and purple, I think. Am I right? Is this it (but it's polar)? https://www.essilorusa.com/products/...zed-sunglasses

AR on tinted lenses isn't a huge problem unless you are expecting the quality you get from Cizal/Duravision/EX3. Almost every AR that is NOT these will just be applied to the lens willy-nilly. If you use house ARs already you probably won't notice any difference. I Crizal everything I can get my hands on, so for me tint and house AR would be a departure from what I regularly provide. I do it, but I warn my customers about the compromise. Half then say nevermind, they want the better durability, the other half say cool, they just want the fun and aren't too concerned about the durability. And backside AR is much less of a problem since it's not going to get beat on as much as the frontside is.

Yes Essilor does have the tinted Crizal sun product, but it is a special order from the big Essilor labs, and I have ordered them three times and been three times dissatisfied with the darkness, hue, or gradient positioning. They did not turn out like the demos. And of course all you can do is remake and hope it turns out better. It didn't. So I don't do them anymore.

[drk]

Ok, Dan Liv, I like the way you break it down:

#1: You are a big proponent of higher-durability ARs. I can get on board with that.
#2: If you do choose to backside AR tinted sunlenses, you don't sweat the quality decrease.
#3: Manufacturer-produced tinted + backside AR lenses are a hassle, so you don't go there.

Right?

[DanLiv]

Ok, Dan Liv, I like the way you break it down:

#1: You are a big proponent of higher-durability ARs. I can get on board with that.
#2: If you do choose to backside AR tinted sunlenses, you don't sweat the quality decrease.
#3: Manufacturer-produced tinted + backside AR lenses are a hassle, so you don't go there.

Right?

You got it!