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jeshimon
Jun 14, 2006, 10:15 AM
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If your gonna be on snow fields and glacier, is OK just to wear a $7 pair of 100% UV protection walmart specs?
8^) :shock:
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doogle
Jun 14, 2006, 10:39 AM
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I did. I can't see a problem with that.
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anykineclimb
Jun 14, 2006, 10:53 AM
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Just be sure they're DARK and are wrap around.
If you can't get wrap around its pretty easy to rig up some side shields with duct tape.
(BTW, this is in a really odd section...)
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rhythm164
Jun 14, 2006, 11:57 AM
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Yea, you want to make sure that sunlight won't reflect off the ground up under the glasses. One advantage of glacier glasses is that they have shields on the sides to prevent this from happening. You can get a pair of Julbos for like 50 bucks, probably even less online. I'd say your peepers are worth the investment.
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bill413
Jun 14, 2006, 1:11 PM
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In reply to: I did. I can't see a problem with that. |
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atg200
Jun 14, 2006, 2:09 PM
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it depends a lot on how high you are going to go. after seeing more than a few cases of snowblindness in the andes(and listening to them groan in pain), i'm not very inclined to push it.
normal sunglasses are probably fine to around 18K feet or so, but anything above that you need the additional UV protection or you stand a real chance of badly damaging your eyes.
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dingus
Jun 14, 2006, 2:38 PM
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In reply to: normal sunglasses are probably fine to around 18K feet or so, but anything above that you need the additional UV protection or you stand a real chance of badly damaging your eyes.
Many sunglasses come with stickers that say '100% UV protection.'
Can you get more than that? 110%?
DMT
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bustaheel
Jun 14, 2006, 3:06 PM
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Besides UV protection, glacier glasses also have a very low light transmission, usually only a few percent. You can get 100% UV glasses that are only slightly tinted. These light galsses are like staring at a lightbulb for a while. There is no UV, but there is white spot where the light bulb was. Now do this with the sun, with its reflection off the snow, all day. Doesn't sound good. I'd at least go get some of the cheep Julbos designed for glacier travel.
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paganmonkeyboy
Jun 14, 2006, 3:24 PM
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In reply to: Besides UV protection, glacier glasses also have a very low light transmission, usually only a few percent.
many glacier glasses will come with a little insert detailing the transmission curve of the lenses and how much they really let into your eyes. Also - many glacier glasses will help attenuate your eyes to the blueshift and block the haze in much the same way a yellow filter on a camera works - you will see clearer, at greater distances, in lower light (with the right glasses).
This is much more than just 100% UV protection. And are you really gonna believe a sticker on some cheapo pair of shades at mallmart ?
I had the cebe $50 plastic glasses from REI. Went through two pairs in the past decade, recommend them highly for light weight and minimal moving parts...and your eyes are worth it, IMHO...
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atg200
Jun 14, 2006, 6:37 PM
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well dingus, i know a bunch of places where you can buy a watch for $7 with a sticker that says "100% genuine rolex". i don't really believe that either, and i'm especially skeptical about implausible claims when it comes to the health of my eyes.
i'm much more willing to trust sunglasses that have an AS 1067 certification, which means about the same thing and hopefully means the glasses have been checked over. if they don't have that sticker, be wary.
i'm not saying you necessarily need glacier glasses, and i don't use them myself unless i am going to be on glaciers above 5000 meters. i do however use good quality sunglasses from manufacturers i trust with certified lenses.
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dingus
Jun 14, 2006, 6:53 PM
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In reply to: well dingus, i know a bunch of places where you can buy a watch for $7 with a sticker that says "100% genuine rolex". i don't really believe that either, and i'm especially skeptical about implausible claims when it comes to the health of my eyes. i'm much more willing to trust sunglasses that have an AS 1067 certification, which means about the same thing and hopefully means the glasses have been checked over. if they don't have that sticker, be wary.
Great points my friend. Exactly what I was driving for mate, thanks.
DMT
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macherry
Jun 14, 2006, 8:10 PM
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macherry moved this thread from Suggestions, Questions & Feedback. to Alpine & Ice.
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tonloc
Jun 14, 2006, 10:27 PM
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im a boulderer and i have a pair...they look cool, especially when you try and grow your beard out a bit, have long dirty hair, wear the most disgusting flannel you can find, you look like a genuine mountain man, and the biddies love that my friend, not gonna pick them up with a 7$ pair of walmart cheapos...
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skiclimb
Jun 14, 2006, 11:01 PM
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In reply to: If your gonna be on snow fields and glacier, is OK just to wear a $7 pair of 100% UV protection walmart specs? 8^) :shock:
I have actually tested cheap and expensive sunglasses in a uv spectroscope lol. Absolutely! They will protect you eyes as well as a $200 pair of glasses. (assuming they are large enough and correct shape) As a biochemist I do a lot of work with uv spectroscopy. Plastics and glass both filter UV radiation about as well as a steel plate. For this reason UV spectroscopy requires the use of expensive quartz materials that allow transmission of UV light.
However cheap glasses tend to reduce visibility and clarity while a good pair can really enhance your vision. One of the great pleasures of mountaineering are the sights .. a good pair of glasses is a worthwhile luxury IMO. I recommend a light rose tint glass.
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greenketch
Jun 14, 2006, 11:36 PM
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Not enough info. The answer lies in what glacier and what time of year and weather conditions and all that. I often wear cheap glasses and all is good. Sometimes I am on an aspect where the sun is really intense and i am on a really clean reflective glacier. On those days the cheap ones are not good enough. Especially the effective lack of side shields.
Just check out the route. If you are going to be on an aspect that faces the sun and the angle is such that a bunch of it is going to reflect up under the glasses then get the good ones.
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bustaheel
Jun 14, 2006, 11:55 PM
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I'd not bother with the cheepos. Wait another 20 years and when your are afflicted with macular degenration and your retinas are bleeding like crazyand you can't see for squat you'll wonder what was the cause.
An extra 50 bucks for years and years of sight.
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skiclimb
Jun 15, 2006, 12:05 AM
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In reply to: I'd not bother with the cheepos. Wait another 20 years and when your are afflicted with macular degenration and your retinas are bleeding like crazyand you can't see for squat you'll wonder what was the cause. An extra 50 bucks for years and years of sight.
wont make a bit of diference in blocking UV... $200 glasses can be poor if they allow lots light in the sides. $7 ones will be great if they wrap around.
The manufacturers of glasses do not have to do ANYTHING to get the material to block UV... glass and plastics do this as part of their physical characteristics. Only consideration for safety is size and shape. sunguards on side can help of course.
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skiclimb
Jun 15, 2006, 12:19 AM
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bleh doubleP
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antiqued
Jun 29, 2006, 12:48 AM
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In reply to: The manufacturers of glasses do not have to do ANYTHING to get the material to block UV... glass and plastics do this as part of their physical characteristics.
This is not true enough. Although everything will absorb somewhere in the UV spectrum, most glasses and pure plastics will allow enough UV through to be dangerous.
I have tested lab 'glasses" (polycarbonate) in a spectrophotometer, and they cut off transmission sharply just below 400nm wavelength (99ish%absorbed). Commonly used optical glasses will cut off between 360nm and 300nm, depending on composition. Common optical plastics (polycarbonates, polystyrene, polyesters, urethanes) are usually transparent down to 320nm or below (note that these are 'classes', not compounds; for example, 'polyester' soda bottles are ethylene-glycol/dimethyl terepthalate polyesters, many other possible members of the class exist, and can have different optical absorbances).
I believe that all eyewear meeting UV transmission standards do so by the inclusion of absorbing species or by the application of an absorbing film, not by the intrinsic properties of the plastic or glass.
Quickly Googled data on 'clear polycarbonate discs' for DVD
UV A 88%
UV B 28%
UV C 0%
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skiclimb
Jun 29, 2006, 1:43 PM
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Perhaps you are correct in that the materials do not block enough UV inherently. I actually havnt tested these materials other than when used in sunglasses. My tests were not a particularly large sample either. Nor did I check to see if they were statistically significant.
However all the sunglasses I checked more than aequately blocked UV. Infact the cheapo ones did slightly better than an expensive pair of glass sunglasses.
However the expensive one also were adequate and enhanced the quality of vision better than cheapo's.
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atg200
Jun 29, 2006, 2:21 PM
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UV isn't the only consideration. good quality glacier glasses let in less visible light as well.
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pastprime
Jun 29, 2006, 3:56 PM
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An aside on price/quality perception:
Long ago I worked in a mountain gear shop in a ski town in Idaho, and we carried a line of sunglasses which, though very good quality, were only $13. a pair. They didn't sell well, but we kept them on because we liked them. One year, the company raised the prices across the board so these same glasses became $35 a pair, though the product itself was unchanged, and these same glasses began to sell very well.
We were also, at the time, the largest volume dealer in the US for a very pricey line of big name imported sunglasses, which gives an idea of what our market was
There are a lot of cheap junk sunglasses in the world, but there are also some very good ones at reasonable prices. One thing I always do when considering sunglasses is hold them about 6-8" in front of my eyes, looking through them at something with a straight line, like a corner in the room. I rotate them up and down and from side to side, seeing if the straight line wiggles as different parts of the lens pass in front of it. Good lenses won't make the lines wiggle, cheesy ones will.
I like rose or brown/amber lenses because the bring out the contrast in flat light conditions, making it easier to define the terrain; and because they make the world a brighter, happier place. I don't care if the colors are distorted. They are distorted into something better than they were.
I agree with the above posts about watching for light coming in around the outside of the glasses, and that the higher up you are, the more you need to worry about light leakage around the edges that you can get away with at lower elevations. And remember exposure to UV is strongly linked to cataracts (sp?), and were your sunglasses whenever you are in bright light, not just at the worst of times.
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