Finished SV Blue Light / HEV lenses

[DanLiv]

I am interested in FSV blue light control lenses, and primarily a pretty inexpensive option to offer as plano or mild plus to emmetropes and CL wearers who do extensive computer work. I have a few sources including Chemistrie (for simple planos and + sphere powers), Nassau lens (full range stock rx poly lenses with blue light AR), and Bluetech (very limited Rx range and strangely expensive, not sure why I would want them), but I don't know of any other suppliers. Anywhere else I can get these FSV lenses?

Thanks!

[RT]

Hoya has FSV Trivex with Recharge AR available.

[Dr. Bill Stacy]

Until Noviolens comes out, probably the cheapest would be to take a cr-39 or tintable poly, add a little yellow tint. If yellow is to weird for the wearer, add a little pink over the yellow to get an apricot or fleshtone appearance. If you want to add AR, do a lab choice AR without any additional UV protection (the additional UV can reflect and concentrate UV off the back surface into the eye and onto the lids)

[ml43]

If you want to add AR, do a lab choice AR without any additional UV protection (the additional UV can reflect and concentrate UV off the back surface into the eye and onto the lids)

Just an FYI, UV AR normally means, UV reflectance off the front, and UV transmittance through the back

if you don't put a UV AR coating on the lens, then you will get what you are describing.



Non UV AR reflectance:

[Dr. Bill Stacy]

We definitely have a difference of opinion here. When I use the term AR with UV protection, I am referring to a true anti-reflection coating on the front, usually with a green hue to the slight reflection off that surface, and a uv blocking ar on the back side, usually with a bluish hue to the slight reflection coming off that surface. Examples of these are Essilor's Avance' and Alize' neither of which offers "non-uv" versions of these coatings. VSP has a version Unity Elite and Unity Plus, both of which allow a non-UV version. All of these are fairly innocuous and are in common use today.

What I think you are referring to as "UV reflectance off the front" and "UV transmittance through the back" are not AR coatings at all, but blue and UV MIRROR coatings ON BOTH SURFACES. Examples of these include Essilor's Prevencia and VSP's TechShield which are unfortunately rapidly gaining popularity with the rise of bluephobia. These coatings are dangerous in that they reflect blue and UV off BOTH front and back. Worse yet, UV reflected off the back surface from light sources located behind the wearer are also CONCENTRATED or FOCUSED on the eye and it's adnexa due to the concavity of the inside surfaces of most lenses. These lenses are indeed very protective of Blue and UV coming from in FRONT of the wearer, but if there are any blue/UV emitters located BEHIND the wearer, they offer a very distinct blue and UV hazard from both reflected and concentrated radiation of these backside sources.

[ml43]

We definitely have a difference of opinion here. When I use the term AR with UV protection, I am referring to a true anti-reflection coating on the front, usually with a green hue to the slight reflection off that surface, and a uv blocking ar on the back side, usually with a bluish hue to the slight reflection coming off that surface. Examples of these are Essilor's Avance' and Alize' neither of which offers "non-uv" versions of these coatings. VSP has a version Unity Elite and Unity Plus, both of which allow a non-UV version. All of these are fairly innocuous and are in common use today.

What I think you are referring to as "UV reflectance off the front" and "UV transmittance through the back" are not AR coatings at all, but blue and UV MIRROR coatings ON BOTH SURFACES. Examples of these include Essilor's Prevencia and VSP's TechShield which are unfortunately rapidly gaining popularity with the rise of bluephobia. These coatings are dangerous in that they reflect blue and UV off BOTH front and back. Worse yet, UV reflected off the back surface from light sources located behind the wearer are also CONCENTRATED or FOCUSED on the eye and it's adnexa due to the concavity of the inside surfaces of most lenses. These lenses are indeed very protective of Blue and UV coming from in FRONT of the wearer, but if there are any blue/UV emitters located BEHIND the wearer, they offer a very distinct blue and UV hazard from both reflected and concentrated radiation of these backside sources.

It's not a difference of opinion.

This is not my opinion, I am informing you of what is available/possible, and what it is call in industry.

Let's clear up some things, because I see you have been spreading misinformation for the past few months.
I'm not saying it's your fault, I have a feeling you either don't talk to your lab reps, or they haven't been communicating with you very well.


1. AR color/residual reflection
- this has very little to do with the actual performance of the AR it self
- residual color is something that is there on purpose and only contributes to about 1-2% difference in reflectance/transmittance of a broadband AR(multi layer)
- in general blue tends to reflect less across the visible spectrum, and green a bit more(hence why zeiss purecoat/crizal sapphire/etc... claim better optics than standard AR)
- you can get a true visible broadband AR in almost any residual reflection/color and have less than 3% reflection

2. UV AR
- UV AR in ophthalmic optics is just a fancy/marketing term for an AR coating on the backside that has its transmission spectrum expanded to include the UV spectrum, or most of it. In precision optics we call this a UV-VIS AR Coating
- These coatings are the same as a regular broadband AR on the front that reflect up to about 20-40% of UVA at peak, depending on the type of AR and what kind of materials are used in the stack.


3. UV "blocking"
- a tradition thin film coating can either help transmit a certain spectrum, reflect a certain spectrum, or absorb a certain spectrum
- remember, AR stacks are very thin, very uniform "lenses" that are deposited by either PVD or CVD on a substrate.
- to my knowledge there is no coating in ophthalmic optics that can absorb UV while increasing transmittance of the visible spectrum at the same time.
- AR coatings that reflect (20-40%)UV are your standard(non UV) broadband coatings
- AR coatings that transmit (most)UV are UV AR coatings, as described above.


Essilors "UV" alize, avance, sapphire, and prevencia all have AR coatings on the back side that transmit UV(reflect less than 5% of UVA)

hope that clears things up for you

edit:
here is a quote from Pete Hanlin, directed to you about crizal UV
"2.) All Crizal lenses are designed to reduce UV reflections from the back surface. Typically, AR stacks are designed to reduce visible reflections using destructive interference (much as Bose headphones are designed to reduce droning noises). However, a stack which destructively interferes with visible wavelengths will often tend to amplify UV wavelengths. A couple years ago, the entire range of Crizal products was optimized to destructively interfere with both visible AND UV wavelengths (that's what the E-SPF messaging is all about)."

destructive interference means, reduced reflection,
therefore more transmittance, given absorption is the same.

[Dr. Bill Stacy]

[QUOTE=ml43;512581]

Let's clear up some things, because I see you have been spreading misinformation for the past few months.
I'm not saying it's your fault, I have a feeling you either don't talk to your lab reps, or they haven't been communicating with you very well.

Actually I do communicate with my lab reps, although they often don't even know as much as people on this forum, so you'll excuse me if I disagree with much of what they say.

1. AR color/residual reflection
- this has very little to do with the actual performance of the AR it self
- residual color is something that is there on purpose and only contributes to about 1-2% difference in reflectance/transmittance of a broadband AR(multi layer)
- in general blue tends to reflect less across the visible spectrum, and green a bit more(hence why zeiss purecoat/crizal sapphire/etc... claim better optics than standard AR)
- you can get a true visible broadband AR in almost any residual reflection/color and have less than 3% reflection

None of the above contradicts anything I've said. It's just useful in identifying and describing various AR coatings.


2. UV AR
- UV AR in ophthalmic optics is just a fancy/marketing term for an AR coating on the backside that has its transmission spectrum expanded to include the UV spectrum, or most of it.

This is exactly backwards. All the big manufacturers of UV AR have an AR coating on the backside that REFLECTS, not TRANSMITS UV. And all thin film coatings reflect and transmit the same wave lengths of light coming from the front (through the lens substrate) and from the back (through the air to the coating).

3. UV "blocking"

- AR coatings that transmit (most)UV are UV AR coatings, as described above.

Again, I think you mean UV AR coatings REFLECT (most)UV, NOT TRANSMIT. Why in the world would anyone want to TRANSMIT UV through a lens, unless it's a BACKSIDE coating, in which case it's a good idea to transmit it on back toward the front of the lens.

Essilors "UV" alize, avance, sapphire, and prevencia all have AR coatings on the back side that transmit UV(reflect less than 5% of UVA.)

Sorry, but I think these all REFLECT UV, as I proved conclusively for the Prevencia lens in the video on www.noviolens.com

Of course Prevencia, Recharge, BlueProtect and TechShield are all Blue and UV REFLECTORS ON BOTH SURFACES not AR coatings at all. But you know that, don't you?

[Chris Ryser]

It's not a difference of opinion.

This is not my opinion, I am informing you of what is available/possible, and what it is call in industry.


3. UV "blocking"
- a tradition thin film coating can either help transmit a certain spectrum, reflect a certain spectrum, or absorb a certain spectrum
- remember, AR stacks are very thin, very uniform "lenses" that are deposited by either PVD or CVD on a substrate.

- to my knowledge there is no coating in ophthalmic optics that can absorb UV while increasing transmittance of the visible spectrum at the same time.

- AR coatings that reflect (20-40%)UV are your standard(non UV) broadband coatings

- AR coatings that transmit (most)UV are UV AR coatings, as described above.

That should clear it up pretty good.

[ml43]

2. UV AR
- UV AR in ophthalmic optics is just a fancy/marketing term for an AR coating on the backside that has its transmission spectrum expanded to include the UV spectrum, or most of it.

This is exactly backwards. All the big manufacturers of UV AR have an AR coating on the backside that REFLECTS, not TRANSMITS UV.

I believe you are misinformed.

UV AR was implemented by most major lens/coating manufacturers after a study done by an OD(Karl Citek, 2008) that found most AR coatings at the time reflected more UV than a standard uncoated lens

https://www.google.com/url?sa=t&rct=...R64PrpgOxRpU6w

this is the reason crizal/essilor, hoya, zeiss, and many other now offer a "UV" AR that has its back side coating designed to transmit, rather than reflect UV

And all thin film coatings reflect and transmit the same wave lengths of light coming from the front (through the lens substrate) and from the back (through the air to the coating).

yes, if and only if you have the same coating on both sides, and in the same stacked order.

3. UV "blocking"

- AR coatings that transmit (most)UV are UV AR coatings, as described above.

Again, I think you mean UV AR coatings REFLECT (most)UV, NOT TRANSMIT. Why in the world would anyone want to TRANSMIT UV through a lens, unless it's a BACKSIDE coating, in which case it's a good idea to transmit it on back toward the front of the lens.

I think you are misunderstanding that UV AR is only a modification to the back side coating.

The front side stays the same(reflects 20-40% of UV)

[ml43]

Sorry for the hijack Daniel.

Have you tried your somo distributor?

[EyeCare Rich]

Thankyou ml43 for the correct description of UV AR treatments. Great descriptions all the way around!

[Dr. Bill Stacy]

So I have to make some corrections in my posts on this thread. I am not a big Essilor user, so I have limited availability of their products to evaluate.

I just looked at a stock transitions VII grey lens with Avance' AR coating, and it appears that both surfaces have a BLUE reflective hue. This surprised me as I'm pretty sure clear lenses with Avance' have a green reflective hue. Maybe someone with connections to Essilor can elaborate on this.

On further testing with blue and UV it appears that indeed there is less UV reflectance off that back side than off the front.

So while I'm not a fan of reflecting visible blue off the back surface, I apologize for implicating the Avance' in reflecting UV off the back side in the way that their Prevencia does, at least for this particular iteration of Avance'.

[Dr. Bill Stacy]

I also appreciate the citation of that 2008 paper on UV reflectance. I kind of got blindsided by all the dismissive comments I received from the manufacturers of the blue/UV reflectors (Zeiss, Essilor, VSP and HOYA) who uniformly stated that the backside reflections are so minute as to be inconsequential. It's actually kind of funny that they thought it was important back in 2008, but now it's no big deal with those dangerous reflectors.

Again, sorry for the errors, but I'm glad for the attention this discussion is finally getting. I hear that some of the formulations are being changed.

[DanLiv]

Have you tried your somo distributor?

Aw SNAP, SOMO Blue Block UltraClear AR! Didn't even know they had it, thanks ml43! Neither ODG nor ABB seems to have it (on their online ordering at least), guess I'll call them.

I just looked at a stock transitions VII grey lens with Avance' AR coating, and it appears that both surfaces have a BLUE reflective hue. This surprised me as I'm pretty sure clear lenses with Avance' have a green reflective hue.

That's the blue non-slip edging topcoat applied to Crizal lenses to keep them from twisting during edging. Clean with alcohol and it will reveal the customary Crizal green.

[Dr. Bill Stacy]

Ah yes, the sacraficial coating. Forgot all about that one in the moment...

[ml43]

Aw SNAP, SOMO Blue Block UltraClear AR! Didn't even know they had it, thanks ml43! Neither ODG nor ABB seems to have it (on their online ordering at least), guess I'll call them.

haha, no worries

I would call Somo Directly, they can you a list of distributors near you that sell/carry what you need.

ABB is ok, but sadly they don't carry somo's full line

So I have to make some corrections in my posts on this thread. I am not a big Essilor user, so I have limited availability of their products to evaluate.

I just looked at a stock transitions VII grey lens with Avance' AR coating, and it appears that both surfaces have a BLUE reflective hue. This surprised me as I'm pretty sure clear lenses with Avance' have a green reflective hue. Maybe someone with connections to Essilor can elaborate on this.

On further testing with blue and UV it appears that indeed there is less UV reflectance off that back side than off the front.

So while I'm not a fan of reflecting visible blue off the back surface, I apologize for implicating the Avance' in reflecting UV off the back side in the way that their Prevencia does, at least for this particular iteration of Avance'.

That's the blue non-slip edging topcoat applied to Crizal lenses to keep them from twisting during edging. Clean with alcohol and it will reveal the customary Crizal green.

I'd also like to add that prevencia has the same coating on the back of the lens as avance, many times it's actually ran in the same cycle

here's more graphic info for you, Bill

https://www.google.com/url?sa=t&rct=...bZlDoGynMzAVPw

[Dr. Bill Stacy]

I'd also like to add that prevencia has the same coating on the back of the lens as avance, many times it's actually ran in the same cycle

here's more graphic info for you, Bill

https://www.google.com/url?sa=t&rct=...bZlDoGynMzAVPw

Thanks for that. Pretty impressive. I'm wondering if the sample of Prevencia dropped off at my office by an Essilor rep actually was a fluke, with the blue mirror on both sides when all Rx lenses have that Forte' on the back side? I wouldn't know as I don't order them. One would think they'd do a sample just like the real thing...

[ml43]

Thanks for that. Pretty impressive. I'm wondering if the sample of Prevencia dropped off at my office by an Essilor rep actually was a fluke, with the blue mirror on both sides when all Rx lenses have that Forte' on the back side? I wouldn't know as I don't order them. One would think they'd do a sample just like the real thing...

easy, alize, avance, forte, and the back side of prevencia should be very similar in terms of residual reflection

the biggest difference is the top coat/hydrophobic layer

if the back side of your prevencia sample isn't green, either it was done wrong, or it has the anti slip coating on it that should be removed

[Paul Smith LDO]

I am interested in FSV blue light control lenses, and primarily a pretty inexpensive option to offer as plano or mild plus to emmetropes and CL wearers who do extensive computer work. I have a few sources including Chemistrie (for simple planos and + sphere powers), Nassau lens (full range stock rx poly lenses with blue light AR), and Bluetech (very limited Rx range and strangely expensive, not sure why I would want them), but I don't know of any other suppliers. Anywhere else I can get these FSV lenses?

Thanks!

Nassau and I believe you can acquire the full line of Somo and Shore.

[Dr. Bill Stacy]

easy, alize, avance, forte, and the back side of prevencia should be very similar in terms of residual reflection

the biggest difference is the top coat/hydrophobic layer

if the back side of your prevencia sample isn't green, either it was done wrong, or it has the anti slip coating on it that should be removed

My sample was just like the other brands, mirror blue on both surfaces. Not the protective blue AR. I will order an Rx pair today to check it out.

[Chris Ryser]

However Polycarbonate lenses stop UV absorbtion at 380 nm, and leave 20% that are transmitting (up to 400 nm) of the damaging rays. Even if ANSI says the limit is at 380 nm, all other sientific tests say it is at about 400 nm.

AR coatings reflect not 100% but only a certain percentage, which will still leave a certain percentage transmitting through the lens, unless the lens material has been treated for full UV absorbance either by the manufacturer or a lab.

AR coatings have been sold because they transmit more light.

It is really not the reflection that counts, at the end it is the absortion level and what comes through the lens and what hits the eyes.

Below is another reminder:

• Department of Natural Sciences, Fordham University, New York City, NY 10023, USA. jroberts@fordham.edu

Abstract

The human eye is constantly exposed to sunlight and artificial lighting. Light transmission through the eye is fundamental to its unique biological functions of directing vision and circadian rhythm, and therefore, light absorbed by the eye must be benign. However, exposure to the intense ambient radiation can pose a hazard particularly if the recipient is over 40 years of age.

This radiation exposure can lead to impaired vision and transient or permanent blindness.Both ultraviolet-A (UV-A) and UV-B induce cataract formation and are not necessary for sight. Ultraviolet radiation is also a risk factor for damage to the retinas of children.

The removal of these wavelengths from ocular exposure will greatly reduce the risk of early cataract and retinal damage.

One way this may be easily done is by wearing sunglasses that block wavelengths below 400 nm (marked 400 on the glasses). However, because of the geometry of the eye, these glasses must be wraparound sunglasses to prevent reflective UV radiation from reaching the eye.

Additional protection may be offered by contact lenses that absorb significant amounts of UV radiation.

In addition to UV radiation, short blue visible light (400-440 nm) is a risk factor for the adult human retina.

This wavelength of light is not essential for sight and not necessary for a circadian rhythm response.

For those over 50 years old, it would be of value to remove these wavelengths of light with specially designed sunglasses or contact lenses to reduce the risk of age-related macular degeneration.


http://www.ncbi.nlm.nih.gov/pubmed/21617534

[Chris Ryser]

See he new thread of blue light soon to have disapeared.
===

No more blue light emitted from LED's is coming

[Slim]

every prevencia lens I have done... about 50-60 a month all look the same. the way I see the colors are. purple | green {lens} green | purple The Green layer looks to be up against the lens on front and rear. The purple shows as a top surface reflection.

sorry for thread jack :(

the green light reflection is off the backside curve, while the purple is off the front...


the green is off the "front" curve here and the purple is off the backside curve.

[Barry Santini]

However Polycarbonate lenses stop UV absorbtion at 380 nm, and leave 20% that are transmitting (up to 400 nm) of the damaging rays. Even if ANSI says the limit is at 380 nm, all other sientific tests say it is at about 400 nm.

But then how you define the cutoff definition for UV makes a BIG impact on the threat of HEVL, yes?

The range from 380 nm to 400nm becomes a battle ground. I'm not sure that most the current HEVL filters have defined how they handle this range, or what their assumptions are about the underlying substrate they are applied to.

Any ideas?

B

[Dr. Bill Stacy]

(quoting: every prevencia lens I have done... about 50-60 a month all look the same. the way I see the colors are. purple | green {lens} green | purple The Green layer looks to be up against the lens on front and rear. The purple shows as a top surface reflection.

sorry for thread jack :(

the green light reflection is off the backside curve, while the purple is off the front...)


I think what you are seeing is a very bright blue reflection off whichever surface you are facing. Your photos show this nicely. The fainter green reflection is coming off the other surface, the one facing away from you. Your light source is fluorescent, emitting both blue and green light. The blue light is mostly reflected back off the first surface it hits, leaving the green to travel through the lens; when it encounters the front surface, there is only green to be reflected, which is only weakly reflected by that surface back toward you. This remaining light is also attenuated somewhat by the lens substrate itself as it makes 2 passes through the lens. (actually there are more than 2 reflections, as the light bounces back and forth many times, but the 3rd and 4th iterations are very faint and you need special lighting to see them.