I've seen some companies advertize thicker temples to occlude indirect light sources. Im unaware of any scientific evidence to support it but it does have a logic and fits your KISS principle.
I've seen some companies advertize thicker temples to occlude indirect light sources. Im unaware of any scientific evidence to support it but it does have a logic and fits your KISS principle.
The problem with guessing and dabbling in specialty tints - particularly when no hard data or information is available about the particular patient and their working environment, is that it is a needle in the proverbial haystack at best. There are SO many possible lighting conditions, vast numbers of light transmission curves from fluorescent tube bulbs, all sorts of different possibilities concerning ballasts, fixtures, diffusers, environmental reflectors/absorbers... Without a lot more information about both person and place, this is a very difficult issue to work out scientifically/medically. Tints like the ol FL-41 are great at making their creators a healthy income based on their marketing, but without personalized testing, application, and proper follow up, there is no way to measure any actual efficacy...or detriment to the patient.
Its difficult, but not impossible. That is why in office tinting is the best for this. Many years ago I managed an OMD practice with a very large post tramatic occular migraine patient base (mostly car accidents). We created a set of "fit overs" with various color combos, yellow to red to brown. In office we were very successful at finding the right color by asking the patient simply to put the fit over's on and seeing which color brought the greatest relief, and holding other tints over that. In the case of where they found relief in two colors, we just mixed those tints.
About 60% of our photophobic patients found significant relief with tints alone. Most of the time, we were successful on the first visit, just in office. So although its impossible to reproduce every light situation, we sent a few patients home or to work with the sample set for those who's needs were more specific to a certain enviroment. They came back and simply told us which colors brought the most relief.
Originally Posted by Uilleann
We have used Drivewear on several cases with good results.
Have you read the studies about the FL-41? Would you rather do nothing for the patient? The goal is to provide symptom relief, not change the world.
I search for solutions, not excuses for failure. You might want to try it sometime; it can be an amazing paradigm shift to finding solutions to problems that do exist and can be solved.
So it's acheap, easy way to improve the lives of these patients......................
"FL-41 lenses are non-invasive, they have no side effects and they're not expensive," Dr. Katz added. "So it's a cheap, easy way to improve the lives of these patients, who in some cases are very disabled by their disease."
Be sure glasses block blue-green. FL-41 lenses are available in optical shops, but Dr. Digre cautioned that some so-called FL-41 lenses are not the real thing. "You really have to know whether the lenses are real or not." she said. "Some lenses can look like FL-41, but they don't act like it. We have done spectral analysis of our lenses to make sure they are blocking the right light".
see all of it--------------------------> http://www.callbpi.com/support/fl-41.htm
Speaking of specialty tints... I had a patient come in yesterday with an RX from his neurologist indicating the necessity of blue tinted specialty lenses that were tinted at 40% for outside use and 10% for inside use because patient is photo sensitive and the tint should decrease the occurrence of patient's seizures. After talking with the patient though, he already has a pair of prescription polarized grey sunglasses that he likes and doesn't want to buy another pair for outside use. Why is it that the doctor thinks having just a 40% blue tint on the glasses for outside would be more beneficial for the patient's use than a polarized lens?
his neurologist indicating the necessity of blue tinted specialty lenses.............
..........................Because the Neurologist is not talking optics, but the nervous system of the patient, a totally different area.
I understand the point Uilleann is trying to make, its very subjective, and he is right. Some opticians like you and me are very subjective, so its in our nature to say "if it works, go for it" . Corning did a large study on their color set in the 1980's, so we have some solid basis in addition to the FL-41 study. The difficulty is that some patients are helped by reds, some by brown, some by crux, some by yellow. Despite the claims by FL-41 I found that many patients need custom mixed colors for maximum relief. Science has not rendered an answer to many of the questions on WHY these one color works with one patient, not with others. And a few are not helped at all. It is difficult.
There is inherent mystery to light, the properties are still not fully understood. Someone just created coated glasses using holes SMALLER than the waves of light, yet light still passes through them. Science cannot fully explain why. Back to particle theory again? Modified wave theory? There will always be mystery in optical, I think thats what makes it fun.
Fortunately tint is cheap, we can in this case afford to shoot from the hip and find some relief for people, even if we fully don't understand why some colors work and some don't. If its snake oil, its at least very cheap snake oil.
I have heard of this before, but only once and never researched it. Looking forward to learning more.
In trying to find the right color for the patient, I would suggest beginning with NOIR medical Technologies filters. They are more economical. I have used many of these over the years. Plum Filter colors 78, 81 and 80 may work. www.noir-medical.com
Bev Heishman, ABOM, NCLC-AC
Thanks Bev, NOIR i believe they purchased/received the rights from Corning, so their colors match the Corning Color set I was talking about...
I agree that it's difficult to simply know which tint will help a given patient, but Ian Jordan used to post very objective-not-subjective answers to similar questions. Is there an accurate testing procedure other than trial and error?
We are on the same wavelength with this, ultimately I would love to go into their environment and test the lighting. Testing would be ideal, but unfortunately the costs and equipment just puts it outside the realm of reality. Yes, you are right also about a detrimental factor when tinkering around with tints or filters, and sometimes the downsides are greater than the upside.
Yes, and Ian would be a great resource to call upon for much greater information and education on the subject. Occupational optometry has been working with some of this in very controlled settings, and there are some (as in Ian's case) who have done extensive research and work to further understanding and workable real-world solutions that don't involve fancy guess work.
While the effects of attempting something like this because of it's relatively low cost (except for that magic FL-41..and yeah, I know all about the studies as the school is just up the block from us) it really isn't any different for a migraine/extreme photophobe/epileptic pt in concept, than throwing random trial lenses in front of a typical patient to "refract" them before making new lenses. While it certainly can be done, there is a risk involved - perhaps even greater with some of these patients than an error in the refraction for an SRx or poorly fabricated progressive design might be with a 'regular' individual.
Proceed if you must, but great caution in these cases would certainly be prudent.
How about finding out if some body else has done some testing at some other times..................................?
There are some reports published as........................
This same phenomenon appeared again when he investigated the environment
of a group of chinchillas whose litters were predominantly male. The chinchillas were
kept in a dark cellar and the breeder used standard incandescent lighting. The only
female offspring had been born from a chinchilla kept by the cellar window. Ott set up a
group of lights that would give a more balanced spectrum and the next litter was
predominantly female, which is more natural to the chinchilla species.
Ott continued his research on effects of light on animals in a study of mink in
natural light (cages with open tops) and those that had deep-pink glass and deep-blue
glass over the cages. The mink kept under pink glass became aggressive and vicious.
Mating became difficult because of the fighting between males and females. The male
also became what is termed "non-working." While mink are normally fierce and handled
with gloves, Ott reported that those kept under blue glass became docile enough to be
handled with bare hands. It was further reported that all males became "working males"
once again. Based on these findings, Ott maintained that the eye is the receptor for the
balanced spectrum.
See all of it ---------------------> http://c.ymcdn.com/sites/www.colts-l...ov-00_20-2.pdf
Sort of good news...Patient did try the visor (with some relief), but a vermillion 30% tint seems to be working! Now the thornier issue - she wants Crizal only, and the tint can't be controlled (or in some cases even done) with Crizal coatings. I happen to be a Crizal fan (I know the ABE fan club will throw tomatoes at me), but we will probably do a Zeiss coating for her final lenses. Thanks everyone for so much input...it was a big help, and gave me lots of food for thought for the next patient with this issue.
Lost and confused in an optical wonderland!
And fit all Chinchillas next to an open window.
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