Crizal UV Launch tomorrow

[kcount]

hmm Essilor loses the Scotchguard name and suddenly comes out with Crizal UV. Coincidence?

[Wes]

Higher altitude = higher UV exposure. Truth.

Yep. I went to school in Aurora Colorado (Denver suburb) in 93. Went to the pool the first sunny weekend In May and got the burn of my life. Hard lesson.

[Speed]

I don't see a Crizal UV that people have been talking about. I see a Crizal Sun on their website and it says -

makes sense....

Less than what?

[Nikolay Angelov]

I think most people agree with the following points:

1. UV=Bad
2. Reduction of UV exposure = Good

So we have a product that claims to reduces UV exposure from surface reflections. This sounds good (see the 2 points above).

However there is no objective data nor tech specifications that i was able to find.

For example, a graph showing the spectral reflectance with versus without the UV optimization.
Percentage drop in reflected UV-A, UV-B and UV-C compared to current AR coatings.

Even something like this but for the UV spectrum would be nice:


For all we know the coating could reduce reflectance in the UV spectrum by 0.001% compared with normal AR coatings.
Which while being an improvement is still rather insignificant.

So does anyone have any hard data on this thing?

[Nikolay Angelov]

http://www.luzerneoptical.com/pdf/crizal-sunshield-sales-aid.pdf

Crizal SunShield™ is the first and only No-Glare lens that incorporates an
optimized AR stack to eliminate backside UV reflections—allowing 30% less*
UV light into the eye than ordinary sun lenses.

* Compared to ordinary sun lenses. Ordinary sun lens defined as a prescription uncoated polycarbonate polarized or tinted lens.

Finally some data . Lets do some quick calculations for a single surface (as in "back surface").

Polycarbonate reflectance = 5.2% of total fallen light.

Visible spectrum + UV-A + UV-B spectrum: 280nm to 750nm

UV spectrum (280nm to 400nm) is 25,53% from the total spectrum (280nm to 750nm).

UV light reflected from an uncoated polycarbonate lens surface is thus 25.53% of 5.2 = 1.32% (of total fallen light on the surface).

A reduction of 30% in reflected UV light as claimed means:

Crizal UV coating lowers the reflected light (in the UV spectrum) from approximately 1.32% to 0.78% of the whole light falling on the surface.
(compared to an uncoated polycarbonate lens)

* I assumed a constant % reflection in all the wavelengths from an uncoated polycarbonate surface.

It would be nice to get a spectral reflectance graph as well

[AustinEyewear]

That is awesome Nikolay. You're making want to go break out the Physics books. Do you need to account for angle of incidence in order to get the whole picture?

[Pogu]

So how many grams of UV is that?

[Nikolay Angelov]

Turns out UV reflectance could be kind of a big deal

Here is an interesting study with actual data (on lenses from CR39, Trivex, poli, high index and more + coatings like Teflon, SuperHiVision, Alize and more):

Anti-reflective coatings reflect ultraviolet radiation
Karl Citek

Optometry (St. Louis, Mo.) 1 March 2008 (volume 79 issue 3 Pages 143-148 DOI: 10.1016/j.optm.2007.08.019)

-------------------------------------------------------------------------
Full article [PDF]:

http://download.journals.elsevierhealth.com/pdfs/journals/1529-1839/PIIS1529183907005775.pdf

Abstract:
Anti-reflective (AR) coatings provide numerous visual benefits to spectacle wearers. However, coating designers and manufacturers seem to have placed little or no emphasis on reflectance of wavelengths outside the visible spectrum. Ultraviolet (UV) radiation from sources behind the wearer can reflect from the back lens surface toward the wearer’s eye. Various clear lens materials, with and without AR coatings, were tested for their transmittance and reflectance properties. Although the transmittance benefits of AR coatings were confirmed, most coatings were found to reflect UV radiation at unacceptably high levels. Tinted sun lenses also were tested with similar results. Frame and lens parameters were evaluated, confirming that eyewear that incorporates a high wrap frame and high base curve lenses can prevent UV radiation from reaching the eye. The findings strongly suggest that clear, flat lenses should not be dispensed for long-term use in sunny environments, even if clip-on tints are provided.

http://www.optometryjaoa.com/article/S1529-1839%2807%2900577-5/abstract

[EyeMaster]

From Essilor: To help explain the importance of eye protection for consumers, Essilor introduces a new index, the Eye-Sun Protection Factor (E-SPF), which rates UV protection from UV light coming at both sides of a lens. The E-SPF system will help consumers understand the level of UV protection provided by their eyeglasses.

So Essilor invents the problem, they introduce something called a "Protection Factor" E-SPF, they make a device to measure it, and of course only a Crizal coating will save you from it. I think about 25 drops of snake oil = E-SPF 25

added:
In patient trials of 12 Essilor employees conducted in France it was proven that Essilor brand Snake Oil wouldn't stick to a Crizal UV lens.

[optilady1]

I have to laugh at this whole conversation. It reminds me of a continuing education I went to a few years ago where the speaker suggested that every patient that we saw should be sold a pair of safety glasses. Every one. Because soccer moms might get hit by a stray soccer ball, speed walkers might walk so fast they might miss a branch and get smacked by it, and lets not forget about exploding tv's.

I'm guessing that there would be a small market a people who would really benifit from the MAXIMUM amount of UV protection, but for the average joe, I'm thinking that a 99% blocking ability would be fine.

We could also sell bubbles with the new coating for people to live in....

[newboy]

I am just loving all of this!! Sheeple, funny!!! As to cr-39 with AR, yeah, I sell it also because I feel 1.74, 1.60, or even trivex in a -.75 sph might be a bit over the top, even for people with more money than brains.

Now to my stupid question of the day. The E machine is telling me now that my AR coated lens is actually increasing the backside reflection of UV? I got it, that's why they dumbed it down for us, it's really non glare as they promote, not anti-reflective. My error. I still can't figure out why it won't compare to my polarized non glare on the water, or near the pool, or even driving in bright sunlight, but that's just me I guess. Off to get another glass of kool aid..... sheeples, Ha funny!!!

Another Essilor hater. Just as boring as those that like Essilor. Form your opinion on the facts, not on your opinion on a company that invests more money in R&D yearly, than any other. Essilor produced the worlds first PAL. Have Essilor ever produced a product you did like ?

AR coatings, do increase the amount of UV reflected back towards the eye. Fact, not opinion.

http://m.youtube.com/#/watch?v=N0IV0p-7WnI&desktop_uri=%2Fwatch%3Fv%3DN0IV0p-7WnI

[kcount]

Another Essilor hater. Just as boring as those that like Essilor. Form your opinion on the facts, not on your opinion on a company that invests more money in R&D yearly, than any other. Essilor produced the worlds first PAL. Have Essilor ever produced a product you did like ?

AR coatings, do increase the amount of UV reflected back towards the eye. Fact, not opinion.

http://m.youtube.com/#/watch?v=N0IV0...%3DN0IV0p-7WnI

The video shown doesn't show or state that "AR coatings, do increase the amount of UV reflected back towards the eye." In point of fact the video show that the lens on the right is simply allowing the UV light to pass through the backside of the lens versus being reflected. More interesting would be a white paper showing why UV light is being reflected in the first place and then how the Crizal product is supposedly managing this. More interesting would be if an independant source would publish data comparing various lens and lens coating as to reflectance, wave length, and durability. Crizal putting out a glossy video does little to sway my ideas much in the same as any company does little to sway my opinions when they publish glossy marketing pieces.

Fact: the First commercially viable PAL was invented by "...Duke Elder in 1922 developed the world's first commercially available PAL (Ultrifo) sold by "Gowlland of Montreal". " While yes Essilor and Zeiss did infact produce the modern PAL with the patent by Bernard Maitenaz, patented in 1953, and introduced by the Société des Lunetiers (which later became part of Essilor) in 1959. More interesting is that before the Comfort the Varilux infinity was sold to Zeiss and renamed under their brand. As a side note in the early days of the Comfort it was often referred to as the VII Comfort due to the then popular naming convention.

As to R&D, While many will argue the point I believe Essilor truely stopped new lens design after the abysmal failure of the Panamic on the market. Each lens after was simply a renamed and re-marketed itteration of the Comfort. Proof of this can be found by asking your lab managers (in non Essilor labs) or independantly (as I did) by simply coparing lens maps side by side. This second avenue does take some leg work on your part but you may be supprised to see the results. This being all said I do believe Essilor has done some remarkable R&D in coatings and I certainly give them their due in that regard.
Now, after all this I believe I can state that I am not an Essilor hater, but, I still prefer to use other designs over the Essilor products. A) I prefer to use independant labs that have a wide selection of product to offer at a fair rate. This would include labs such as Luzern and my preferred lab of Laramy-K. There are other labs I could name but I believe given some research you will find these two labs named time and again here on Optiboard. B) I do not believe Essilor's costs are justified given the product provided. This is entirely my opinion and as such is subject to many a sling and arrow but, being that I'm the boss my choice is, in the end, law.

Oh, and on your final question, did "...Essilor ever make a product I did like?" yes, after 20 years selling exclusively Essilor they did a great juob with the Comfort. these days I prefer

[Uilleann]

Another Essilor hater.

These boards are full of 'em.

[Darryl Meister]

Duke Elder in 1922 developed the world's first commercially available PAL (Ultrifo) sold by "Gowlland of Montreal

Just a couple of clarifications: Duke-Elder wrote about the lens, but he did not invent it. Henry Gowlland invented the progressive lens that Duke-Elder was referring to, with patents published in 1909 and 1914. Estelle Glancy of AO invented what is arguably the first single-side progressive lens, although her lens design did not have a traditional progressive corridor. And, of course, Owen Aves still holds the distinction of being the first to produce the idea of a progressive lens in 1907.

We'll now return you back to our regularly scheduled programming...

Best regards,
Darryl

[newboy]

These boards are full of 'em.

You're not wrong.

The E-SPF protocol and measurements has been reviewed by independent third parties: Key US researcher on UV hazard, Karl Citek, endorses the E-SPF protocol and values.
Dr. Karl Citek is a Professor of Optometry in Oregon, USA. He is an independent specialist in ophthalmic optics and one of the first researchers to have published on the hazards linked to UV back side reflection. He has scientifically validated Essilor’s E-SPF evaluation system formula.

Let's see how many of you are quick to discredit Dr Citek. He produced his findings on UV back side reflection independently, long before Essilor produced Crizal UV.