I suspect what you heard was "Transitions," not "Trivex," and that is true; photochromic lenses are HEV blockers by accident of design.Originally Posted by Prentice Pro 9000
I suspect what you heard was "Transitions," not "Trivex," and that is true; photochromic lenses are HEV blockers by accident of design.
I'm Andrew Hamm and I approve this message.
Optical Training Institute course "What Blue Light Can Do: Harm or Help".
Just signed up for this Jobson CE course and thought I'd share the first few paragraphs.
Overview
Blue light can be beneficial or harmful, depending on when and how your patient is exposed to it. The eye care professional (ECP) can provide maximum protection from the harmful aspects of blue light by offering patient education, lens options and other beneficial methods to protect the eye. This course will assist the ECP to broaden his or her understanding of blue light, how it can help or harm the patient, as well as give practical recommendations for patient care.
Hazards of blue light is not a new concept
The hazards of blue light have been known for several decades. Historically, the idea of altering which wavelengths could reach the eye has been promoted in various ways. As early as 1750 ocular professional David Ayscough promoted the idea that "glaring light" could be favorably altered by the use of tinted lenses. In past years, Bolle issued the "tennis advantage" lens, which had a purple hue and could favorably enhance the appearance of a white or yellow tennis ball. Bolle now markets various sun lenses for athletic visual enhancement.
While all of the research is not in, there is enough evidence to show that blue light can damage retinal cells, wreak havoc with the circadian rhythm and even contribute to immune system deficiencies. Blue light causes part of the phenomenon known as "digital strain" or "digital device syndrome". Physical manifestations of digital strain are neck, shoulder and back pain; headaches; and problems specific to the eyes known as "digital eye strain", which includes blurred vision and dry eyes. In spite of the symptoms, approximately 35% of American adults say they aren't concerned about the impact of digital usage on their eyes. Fortunately the ECP has easy-to-offer solutions for digital eye strain and blue light problems.
While every patient should be made aware of blue light hazards, four types of patients can especially benefit from blue light protection: patients with macular degeneration, heavy technology users, children and post-cataract patients.
cooooorrectomundo. WhatÂ’s funny is that there are spectral transmission charts readily available for anybody but I guess thatÂ’s a little advanced for some folks. ThatÂ’s the last time I take anybody at their word.
btw, off topic but kinda on topic with regards to taking people at their word: I was talking to a Varilux rep and asked “what’s the corridor range for Comort Max” to which he replied oh I don’t know maybe 14 to 35mm. Bruhhhh… a 35mm corridor sounds like a good idea to you? Might want to check on that.
As I recall the original Comfort was marketed as a suggested fit height of at least 24mm. This was when frames were quite large. When narrow frames became fashionable they were magically now working at 18mm heights.
It took a while for the truth to come out that 85% of the add power was consider "full power".
Then the Comfort Short came out and the intermediate got squeezed.
for my opinion (which does not count for much) I feel like the intermediate is kind of terrible for the majority of modern day use. I do like the Zeiss I and the Hoya MyStyle iD “design” for a little beefed up intermediate. But I think these long corridors are not great. So, coming back around to the 85% add power, I can kind of understand if the thinking behind it is: we need less add because people are looking at their phone a little further away than 16mm.
…..And, because of the 85% is enough claim, hordes of docs wrote on their Rx’s, “ 2.00 add, +2.25 if progressive.” AND, I still know a doc that does this to this day, it’s not like he’s that old school, grad in ‘98. I tried, (numerous times) to tell him about the draw backs of over rx’ing adds on pal’s. ( Narrower corridor the higher the add, modern FF’s address this, adaption to drastic change, ect..)……His answer for continuing……
” It gives them plenty of add so they don’t have to buy glasses so often…..” ( I kid not..)
Granted, he worked in an OMD location, had no finacial benefit from the optical.
One explanation that I recall is that the French used 36cm instead of 40cm for the standard work distance. Here's Darryl's take from an old thread.
https://www.optiboard.com/forums/sho...3619#post23619Some ODs over-plus or "bump" the add power with progressive lenses for one of two reasons:
1. Years ago, the old Varilux II lenses were introduced, which produced excess plus power because of the asphericity in the periphery of the lens. Consequently, some advocated increasing the add power in conjunction with extra minus in the distance power to compensate for this effect. Many "old-timers" might still take this approach. However, lenses are no longer designed like this, so it is not necessary today.
2. Many eyecare professionals also increased the add power with progressive lenses in an attempt to allow the patient to realize his/her full add power at a shorter distance from the fitting cross, particularly in small frames. In a situation where the minimum fitting height cannot be achieved, the patient may be better served by having the frame lowered slightly, selecting a slightly larger frame style, or of course by using a progressive lens style designed for smaller frames -- like AO Compact.
There are several good reasons not to bump the add power with progressive lenses:
1. At least one study has shown that more patients prefer the prescribed add power for progressive addition lenses to the over-plussed add power.
2. Increasing the add power effectively shifts the patient’s area of clear vision up from the near zone and into the progressive corridor, which is often the narrowest region of the lens.
3. Increasing the add power increases the level of unwanted blur in the periphery of the lenses and narrows the areas of clear vision through the lens.
4. Increasing the add power beyond what the patient requires needlessly restricts the patient’s depth of field -- the range of viewing distances through which the patient can clearly see his/her reading materials at near.
Best regards,
Darryl
Science is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
My take is from practical experience.
First of all, a 1/4D variance is vanishingly small. Give or take 0.25 and nobody notices.
Second, of course you don't want to use more add than needed because you jack up the lens.
But the above listed concerns of 1.) reduced depth of focus, and 2.) "making" the patient use the corridor instead of the near zone is really just an academic concern. Never happens.
It's heartwarming to see after 5 years in the wilderness familiar faces still fighting off blue light hysteria here on Optiboard. Glad we finally got that settled once and for all. ;P
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