Another thought, If the sphincters in our bodys strenghened or weekend with use, all those people who are full of **** would really be a bunch of tight @$$es.
Life is too short to drink cheap beer:cheers:
Yes
No
Don't Care
Another thought, If the sphincters in our bodys strenghened or weekend with use, all those people who are full of **** would really be a bunch of tight @$$es.
Life is too short to drink cheap beer:cheers:
I'm On Harry's side. About the Transitions AND the pie.
I think it's important to remember that Trasitions or any photochromics dont change instantly. Whne a child leaves school to go in the playground, there is a lag time where the lens is starting to darken and the pupil is constricting to respond to the increased light.
If the technology ever got to the point where the lenses instantly changed from light to dark and back, I may rethink this position.
LOL! Although a funny thought, it's not that far away from the truth. Think Kageling ;)Stopper said:
Another thought, If the sphincters in our bodys strenghened or weekend with use, all those people who are full of **** would really be a bunch of tight @$$es.
Life is too short to drink cheap beer:cheers:
Again I agree with Harry on the involuntary muscle responses, but does having a tinted lens in front of the eye not lessen the need for this response? My heart beating is involuntary, however if I become sedentary and overweight just getting up off the couch could make me light headed and cause my heart to run the 100 yard dash where as if I were more active my heart would work more efficiently and I wouldn't have this problem. It is an involuntary muscle repsonse and yet it adapts to conditioning (positive or negative) as do the lungs and other muscles and organs. Involuntary in their basic actions, not involuntary in their response to conditioning.
My primary point is not that these things "are" a detriment but rather that it could cause a problem either temporary or permanent and we just don't know to what extent. There is no test for this that I'm aware of so I base my position on my knowledge of muscles voluntary and involuntary. They all respond and adapt to conditioning.
"Also the analogy to skeletal muscle and atropy or strengthening from no use or full use doesn't fly. Different types of muscles."
Yes, different types of muscles but they all adapt and respond to conditioning. So then I should assume by what you've said above that certain muscle strengthening exercises used by OD's and MD's are a waist of time then? Fixation is both voluntary and involuntary with the emphasis on "voluntary" (extrinsic muscles) but accomdative is voluntary and involuntary with the emphasis on "involuntary" (intraocular muscles) There are exercises, devices and tests used to determine and rectify these problems, Yes?
Please forgive me as I'm not trying to be argumentative but rather curious. Not so much curious of functions but rather why someone, anyone would say "Nope. Doesn't happen." when there is nothing definitive to say one way or the other. I'm presenting what I know about muscle function and adaptation to stresses so why are the muscles of the eye not affected? I would like to know.
Thanks in advance,
Darris C.
Darris,
I understand and appreciate what you are saying but I just don't think this is a problem. (Like you, not trying to be argumentative). You are correct, there aren't any studies that I know of that say one way or the other. I go in and out of dark rooms all day and I don't think my Iris is becoming more muscular and bulking up.
Again remember that most of the light and dark adaptation occurs at the receptor level, not due to apeture size of the pupil.
Thanks for the continued good discussion
Since mine was the first decenting vote on this thread, I'd like to add one more thought. Darris makes some very sound observations. All muscles react to activity, both voluntary and involuntary. It is also true that we have no real data to base a prognosis on. Here's my question:
If we don't know for sure, is it responsible to go ahead and take a chance or more responsible to try to find out for sure.
When they introduced rabbits to Australia, they were pretty sure no lasting harm would come, and there were certain benefits in the short term. The same disaster occurred with other domestic animals when they were introduced. Now the problem can't be fixed.
The point? If you are going to err, err on the side of caution. We don't want to do any harm while we're trying to do good.
:D
shutterbug
If you take as a given, that ultra violet radiation (light) has been directly linked to the development of cataracts and macular degeneration, then to err on the side of caution would be to have everyone wearing protection from these burning rays of the sun.
Ergo it follows that you are in favor of the pediatric use of Transitions lenses after all. :D :D
hj
HJ - Heaven forbid! No, there are much better options. I DO recommend polycarbonate for its strength, and it is an excellent UV filter for both UVA and UVB.
:D
shutterbug
Why not Trivex which does all of the above and is stronger. I really think that question is being beaten to death in another thread but have at it if you will. I thought that I had you convinced for a moment but no soap I surmise. At least no one is saying a lens causes light sensitivity!
:D :D :D
You folks in Iowa have any snow yet??
hj
hj - No snow yet - we're still in the 60-80 degree range. I'd keep it there if I could!
BTW, no one is saying a lens doesn't cause light sensitivity either.
Just that we don't know yet.
:cheers:
Best I could do Harry.
Good Afternoon Everyone,
Great thread, I really enjoy the discussion and points of view this group brings to the table.
The point I want to emphasize, that has not really been discussed, is that cataracts and Age Related Macular Degeneration are linked to cumulative exposure over a whole lifetime.
Childrens eyes (lenses) transmit 75% of the UV at age 10 and only 10% by age 25[1], as well as the fact that children spend more time outdoors than adults (up to 80% of your lifetime UV exposure occurs before the age of 18 [2].
In discussing Photophobia, it is important to emphasize that this is a symptom and not a disease. http://www.spedex.com/resource/docum...tophobia.html.
When one is experiencing photophobia, you want to identify the underlying pathology. Our research information group was unable to identify any papers dealing with photophobia in children as a result of wearing sunglasses.
Another point for dispensing to pediatrics is that Transitions®Lenses reduce the amount of Blue light that has been linked to the development of Cataracts and Age Related Macular Degeneration..[3][4]
Transitions Gray absorbs 78% of the Blue region and Transitions Brown absorb 80%. You can see the Spectral Transmission charts in Tech Notes on our web page.
A UV coated clear lense will not serve this need.
You may want to to visit the FUBI (Fashion, UV, Blue Light, IR) site too. http://www.fubisystem.com.
[1] Lermans: Direct and Photosensitized UV Radiation and the Eye: Experimental and Clinical Observations. Metab Pediatr Sys Ophthalmol 6:27-32, 1982.
[2] Young, S; Sands, J. Sun and the eye: Prevention and Detection of Light-Induced Diseases, Clinics in Dermatology 1998:16:477-485.
[3] Am. Optical ***. Sunglasses Consumer Reports, 1988, 53(8), 504-509.
[4] Hall, G.; Schultmeyer, M. Optometry, 2002, 73:7,
As a few Optiboarders refered to "err on the safe side", the more research (here and overseas) being done on UV exposure leans to photochromic or fixed tint lenses as the best overall protection for your eyes.
Australia is a great example because the inhabitants suffer the highest rates of skin cancer anywhere. In 1980, the Anti-Cancer Council of Victoria launched "Slip! Slop! Slap!" (Slip on a shirt, slop on sunblock, slap on a hat!). This evolved to the SUNSMART Program. On aspect of this program is that in many Australian schools, students are not permitted to play outdoors in summer months without a hat, sunblock and, in some cases, sunglasses. ("the Slip! Slop! Slap! Wrap!) (-with wrapping a sunglass added.) [Note, I do not see much on their website about sunglasses, but UV damage to skin, face etc. is one of the things we report in the Light, Sight and Photochromics monograph.] http://www.cancervic.org.au/cancer1/...2/20021117.htm
Sorry for the long post, just wanted to add more information and leads to the discussion.
I will be at the East West Eye Conference at the Cleveland Convention Center for the rest of the week. If any Optiboarders are around please stop and say hello at Booth 308.
best to all
Jim
Jim Schafer
Retired From PPG Industries/
Transitions Optical, Inc.
When you win, say nothing. When you lose, say even less.
Paul Brown
Sorry I haven't paid attention to this post in a few days.Stopper said:
Darris,
I understand and appreciate what you are saying but I just don't think this is a problem. (Like you, not trying to be argumentative). You are correct, there aren't any studies that I know of that say one way or the other. I go in and out of dark rooms all day and I don't think my Iris is becoming more muscular and bulking up.
Again remember that most of the light and dark adaptation occurs at the receptor level, not due to apeture size of the pupil.
Thanks for the continued good discussion
I realize what you are referring to regarding the receptor levels but you're on the wrong page. The pupil physically constricts to limit the amount of light passing in to the retina which is a muscle reaction not a receptor reaction. Going from light to dark and dark to light is a receptor function but has little or nothing to do with the muscle responses of the Iris. If the intraocular muscles are limited in their function then they cannot work as efficiently to contract the pupil allowing more light to pass through when unshaded hypothetically speaking.
Let's talk a little about muscles and their structure and function. I'm a power lifter and weight trainer as well as having a pretty good understanding of most functions of the body (Just for some background, when my wife gets done with nursing school in May I'm going to finish what I need for my Sciences and apply to Medical school)
As to the muscles of the eye that control the reactions of the Iris, "bulking up" in the manner that you appear to be describing; doesn't work that way. Different excercise creates thickening or toning (lengthening and thinning) of the muscle itself. "Bulking" requires increased resistance to the point of failure to make gains that would be considered "bulking." Isometric, although resistance, will tone and thin a muscle. More efficient? Yes. Bulk? No. Putting or not putting a tinted lenses in front of the eye would be isometric in its function only. Anything one does to lessen the need for a muscle to operate fully will decrease its efficiency, plain and simply, regardless of the kind of muscle or its location. Will it make people blind? No, but more light sensitivity due to less pupil contraction is very plausible IMO.
Harry said:
"If you take as a given, that ultra violet radiation (light) has been directly linked to the development of cataracts and macular degeneration, then to err on the side of caution would be to have everyone wearing protection from these burning rays of the sun.
Ergo it follows that you are in favor of the pediatric use of Transitions lenses after all."
It's already been discussed that you can block out 100% of Ultraviolet light with a clear lenses. Tinting or changeable tinted lenses block out, additionally, a percentage of the visible light spectrum as well as the invisible light spectrums of UV-A, B and C. I realize you are kidding around and it is funny ;) BUT to err on the side of caution and have everyone wearing protection from these harmful burning rays? Well...guess what? That's what is being done already. Sunscreens for the skin, UV for lenses, PSA's for the same. Even an uncoated stock plastic lens will block 30 to 40% of UV and most skin care products have UV blockers in them. Even my bug repellent has UV protection in it. It is a problem and it is being addressed.
Again I will say that long term effects of tinted lenses on pediatrics is completely unknown. Do I think it's a problem? Not based on my, as well as others lack of knowledge on the subject due to no known test for such a thing. To me this subject equates to this:
Me: "Does this create or cause a problem knowing muscle function?"
Other: "No."
Me: "How do you know?"
Other: "Because it doesn't."
Me: "Based on what?"
Other: "This is a silly discussion."
And that's how it seems to play out to me. Not saying I'm right or wrong and not saying anyone else is right or wrong, but the fact is we don't know and are apathetic about it. So much for Science and research I guess.
Take care everyone,
Darris C.
Darris - Don't give up yet, you're just getting warmed up!
:cheers:
Dale
Jim,
There is published material on Australian studies regarding children and UV protection and sunwear.
http://www.extenza-eps.com/extenza/l...&type=abstract
Knowledge of sunlight effects on the eyes and protective behaviors in adolescents
Author(s): Graham A. Lee MBBS 1 | Lawrence W. Hirst MD 2 | Mary Sheehan Ph.D. 3
Article DOI: 10.1076/opep.6.3.171.1501
Ophthalmic Epidemiology
Print ISSN: 0928-6586
Volume: 6 | Issue: 3
Cover date: September 1999
Page(s): 171-180
Abstract text
The knowledge of the effects of sunlight on the eyes and protective behaviors were studied in an adolescent population. A group of 652 systematically sampled students aged between 13 and 17 years was surveyed with a standardized questionnaire in Brisbane, Australia in October-November, 1995. Survey data on the knowledge of sunlight effects on the eyes, ultraviolet light, eye and body protection as well as risk factors for ultraviolet (UV) exposure were relatively ranked and totalled to give overall scores. Of the 652 subjects, 330 (51%) were female. Most subjects (568 or 88%) were aged between 15 and 16 years. Overall, this group of subjects demonstrated a moderate level of knowledge with respect to UV, sunlight and the eyes. The knowledge of the effects of sunlight and body protection was higher than the knowledge of the effects of sunlight and eye protection. Almost three-quarters (462 or 71%) of the subjects owned a pair of sunglasses. The mean age at which subjects started to wear sunglasses was 10.4 years. However, most subjects (528 or 81%) only wore sunglasses occasionally or not at all. The reported frequency of wearing sunglasses was significantly related to personal, family and peer attitudes to such use, but not to media advertizing. Assessment of adolescent knowledge is important in the formulation of health promotion strategies designed to prevent excessive UV exposure at this young age.
Author(s) affiliations
1. Department of Ophthalmology, Princess Alexandra Hospital
2. Department of Ophthalmology, Princess Alexandra Hospital
3. School of Social Science, Queensland University of Technology
I just have to muddy the water a bit more :D
We all agree that UV entering the eye is a bad thing. Some have implied that transitions are a good thing since in the darkened state they are excellent UV blockers and therefore should be recommended to children.
Some of us have offered that the transitions could actually cause harm in the way of weakening the muscles that contract to close the iris. This seems to be discounted too easily by most of you.
So how about this - since the transition lens (or sunglass lens) reduces the intensity of the light entering the eye, the natural response is an opening of the iris. This in turn MIGHT allow more UV to enter from the sides of the eye (unprotected) and MIGHT have long term impact on the health of the eye.
Clear UV blockers, either applied to the lens or inherent in the lens itself allow the iris to function normally and COULD provide more protection in the long run, since more light is restricted from ALL directions.
What do you think?
shutterbug
To Shutterbug,
I doubt it!
hj
PS Transitions filters UV light when in its clear state as well.
hj - that's ok, most who said yes to the poll probably look at life through tinted glasses (rose) too!
ps - If you put transition (plastic) under black light in a UV measuring devise you can actually see it increase in effectivness as it gets darker. Not much better than plastic in it's clear state.
shutterbug
Jim,Jim Schafer said:
Childrens eyes (lenses) transmit 75% of the UV at age 10 and only 10% by age 25[1], as well as the fact that children spend more time outdoors than adults (up to 80% of your lifetime UV exposure occurs before the age of 18 [2].
I have always thought that the lens prevented UV from reaching the retina. It seems that's true only for adults. If there is a relationship between UV and ARMD, the majority of damage might be occurring in our formative years. I wonder if there are studies of the population born before 1940 who were exposed to a higher than average amount of direct sunlight, and their rate of ARMD presently.
Robert
Below is a Q & A from the current issue of Eyecare Business.
Q In a recent "Ask the Labs," you talked about putting photochromic polycarbonate lenses on children. In light of your comments, I have two questions: 1) I recall reading several years ago that putting tints on children prior to puberty makes them more susceptible to photophobia as adults. I don't know if this applies to the modern photo-chromics. Comments? And 2) Does the photochromic feature retard the impact resistance of polycarbonate in any way?
A Here are your answers: 1) Your caution with tints is commendable. Dr. Eric Borsting, chief of pediatrics at Southern California College of Optometry, says he believes past concerns about long-term effects of tints on children came from the fact the lenses tend to be worn under widely varying circumstances. A solid tint can be useful in bright light situations, but would be counter-productive under lowlight circumstances (overcast days, indoors, evenings, in movies, or watching TV). He points out that modern photochromics eliminate those concerns since the lens adapts quickly to changing light conditions. 2) You'll be pleased to know there is no reduction of impact protection with photochromic poly. The photochromic treatment is on the front surface and does not affect the molecular structure throughout the substrate.
No NO NO
This is too complicated for me.
My experience with just tints for children:
If you make them a prescription clear and tinted pair of glasses eventualy i see them using suns for allt he time wear!(the clear pair either lost or broken)
Please clear this up!
Shuterbug, are you saying that the UV filtration increases as the Transitions gets darker? My understanding is that the lens is inherently a UV blocker. The only changes in transmission occur in the visible spectrum. I haven't confirmed this but thats what I think I remember. Memory fades with advancing years :D
hj
HC
I don't think anything that is not completely opaque is a 100% blocker of anything (despite adds to the contrary). If a photochomic lens transmitts 2% of UV at 98% transmission it will transmitt 2% of 40% when it is transmitting only 40%.
Chip
Chip et al,
For Transitions, but I assume (with the full knowledge that there are 3 words contained in that word) that it will fall somewhere in the vicinity of other lenses treated to filter UV light. Usually in the vicinity of 98% up to 400 nanometers. The transitions lens in its clear state will filter out 98 % of UV . Thats a period.For the purposes of eye safety that is considered acceptable, and its good enough for me.My only point in continuing this dialog is to restate that Transitions lenses do not create photosensitivity.
The view from Fredricksburg VA today.
hj
A chart on the BPI Photometer website states:
http://www.callbpi.com/support/photread.html
Typical UV Transmittances
LENS MATERIAL ----------- UV B Trans. ----------- UV A Trans.
Photogray Extra, faded -------- 0.0 -------------------- 9.6
Photogray Extra, darkened ---- 0.0 -------------------- 2.7
Transitions Plus, faded --------- 0.0 -------------------- 1.0
Transitions Plus, darkened ----- 0.0 ------------------- 1.1
Here is a chart on the X-CEL Optical Company's website:
http://www.x-celoptical.com/UV%20light.htm
Transitions are at the bottom of the chart and the numbers represent data when Transitions are at a darkened state.
hj -
The plastic transition blocks about 20% (or less) of uv in its normal undarkened state. As it darkens, the UV protection increases. Of course polycarbonate lenses are great UV filters even in the clear state, and with the addition of high index transitions you also find good UV protection (not always great though) in their natural state.
If your lab has a spectrometer you can verify this yourself. Ask them to put a plastic transition lens into it and you can watch it change and increase UV blockage. I think you are not alone in the idea that they protect us from UV all of the time. However, since the newer transitions darken so much faster I wouldn't worry too much about lack of protection. When you need it, it's there! Incidently, the change to dark is triggered by UV, not visible light. The change back to clear in increased with some natural light - it changes slower in total darkness. Strange, huh?
shutterbug
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