Filters and filtration

[Robert Martellaro]

Wow, nice clean graphs. Maybe too clean. I'm always a bit suspicious when I see 0.00 or 100% anywhere, but will send Chris some real lenses to test on his machine. Should get some results pretty soon. I'll ship out some lenses Monday.

The charts from RT's link to Opticampus are from "Spectral Transmittance of Lens Materials" By Daniel Torgerson OLA 1998.

Blue light transmission of various tints and materials, plano spheres.

Brown #3 CR39 1.8mm 1.9%

Gray #3 CR39 1.8mm 10.6%

Green #3 CR39 1.8mm 16.8%

Photogray Extra Darkened 2.0mm 25.7%

Photobrown Extra Darkened 2.1mm 21.1%

Photogray Thin & Dark Darkened 2.0mm 16.7%

Here's the spectral transmittance of clear polycarbonate and the methodology.

[Uilleann]

I believe you are forgetting that, just like pharm companies, you must create the demand.

for the record, not to argue for or against,
but the same can be said for selling impact resistant lenses, polarized lenses, anti reflective coatings, titanium frames, etc...

none of these things are to treat or cure a medically proven harmful effect

I agree with your assessment here. Though impact resistance is a tangible benefit to lenses - particularly for certain demographics such as pediatric, geriatric or industrial applications. Polarization reduces measurable glare in a wide variety of scenarios, and can be particularly helpful increasing safety through clarity of vision for activities such as driving, or enjoyment of hobbies such as fishing (to name just a couple). AR is a no brainer for maximizing light transmission as well as increasing scratch resistance and cosmetic appeal all at once. These are all easily demonstrable benefits to a patient.

Rather different than the blue light boogey man being so heavily pushed by so many...

[MikeAurelius]

"They tell you what to be afraid of, then try to sell you a solution to your worries."

[Dr. Bill Stacy]

Here's a link to some info with lots of pretty good scientific references, for the blue skeptics, who may have to get over that it's used by Crizal in ads.

http://www.crizalusa.com/content/dam...hite-Paper.pdf

[Joe Zewe]

Here's a link to some info with lots of pretty good scientific references, for the blue skeptics, who may have to get over that it's used by Crizal in ads.

http://www.crizalusa.com/content/dam...hite-Paper.pdf

Another good source is the Vision Council's Digtial Eyestrain Report which also include credible references and sources.

https://www.thevisioncouncil.org/sit...Report2015.pdf

[AngeHamm]

Another good source is the Vision Council's Digtial Eyestrain Report which also include credible references and sources.

https://www.thevisioncouncil.org/sit...Report2015.pdf

This is the source that has generally-skeptical me seriously exploring blue-blocking options.

[Uilleann]

Haven't had a chance to look at the Essilor paper yet, but the VC's is absolutely chock full of terms like: "may damage", "the issue is nascent", "possible link", "emerging research", "could lead", "might be detrimental"...none of which instills much personal faith whatsoever of the veracity of the science employed to reach the conclusions they have.

[Dr. Bill Stacy]

Haven't had a chance to look at the Essilor paper yet, but the VC's is absolutely chock full of terms like: "may damage", "the issue is nascent", "possible link", "emerging research", "could lead", "might be detrimental"...none of which instills much personal faith whatsoever of the veracity of the science employed to reach the conclusions they have.

You'd feel "more personal faith" if they instead said "always damages", "is ubiquitous", "100% linked", "centuries old established science", "invariably leads" and "is universally detrimental"?

I'd run not walk away from anyone using the lexicon of charlatans and Madison Ave.

[MikeAurelius]

Haven't had a chance to look at the Essilor paper yet, but the VC's is absolutely chock full of terms like: "may damage", "the issue is nascent", "possible link", "emerging research", "could lead", "might be detrimental"...none of which instills much personal faith whatsoever of the veracity of the science employed to reach the conclusions they have.

Weasel words.

[Dr. Bill Stacy]

Probably the reason that the smart weasels can't communicate well with the animals who run in herds.

[Lee H]

Haven't had a chance to look at the Essilor paper yet, but the VC's is absolutely chock full of terms like: "may damage", "the issue is nascent", "possible link", "emerging research", "could lead", "might be detrimental"...none of which instills much personal faith whatsoever of the veracity of the science employed to reach the conclusions they have.

Time will tell. I really do hope you are right and there is not any harm being done by all of the blue light exposure. . With that being said, I am taking precautions. I really enjoy my BluTech lenses and I have several pair of TheraBlue lenses on order. More importantly, I have ordered pairs for both of my children who are both deaf. I do not want to wait until there is 100% proof of retina damage or a definite link to AMD. I can't imagine what their life would be like without their eyesight. I'm not on here to sell anyone on anything but thought I would share my thoughts on the issue.


full disclosure - I work for Luzerne Optical

[Dr. Bill Stacy]

I too hope the blue thing turns out to be no big deal. However, I agree that being careful is a good idea, and blocking non-natural sources of high energy visible light is something I'm interested in pursuing, however the science turns out.

Kudos to you for trying to protect your daughters. I don't think blocking short wave blue has any harmful consequences.

[Uilleann]

I agree of course, that caution is prudent - where warranted.

But this blue light craze - at least at this point - still appears to be far more rooted in marketing bias, and profit motivated development of lenses, rather than factually based, independently tested and reproduced, peer reviewed science. At best, looking at the whole premise with an objective eye, it appears to be a lot of hype over nothing.

But hype does sell lots and lots of expensive lenses doesn't it?

[Dr. Bill Stacy]

In some offices, maybe, but not mine. At least not the expensive (Recharge, Prevencia, etc) blue reflector lenses, due to the danger of UV reflection inherent in those lenses, and due to their more or less hideous appearance (the above plus BlueTech).

But right now I am recommending a light yellow or light apricot tint which is cheap to add to just about any lens for anyone who admits to heavy cell phone/gaming/tablet/laptop use and/or any computer use that has lots of blue that can't be easily turned off (some games have lots and lots of blue and violet screens that are not adjustable, and these are of course very popular with kids).

As Groucho once said "It couldn't hoit"...

And by the way, most of the people on this forum are in this business to make money as well as to help humanity, so "lots and lots" of lenses is good for them, both cheap kinds and expensive kinds.

[radiology]

Any one know the percentage of blue light blocking by Hoya blue control lenses ?