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Old 01-15-2009, 07:27 AM   #1 (permalink)
Yarp.
 
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the sun and blindness

I'm curious about how the sun damages eyesight...

Can you harm your eyes by looking at the sun's reflection in a window?

How long would you need to be looking directly at the sun to cause irreparable damage?

Sometimes I'll be sleeping in a car while facing the sun and will feel pain in my eyes when hit full on by the sunlight, even though my eyes are closed. Does that pain mean the exposure has cause damage, despite my eyes being closed?
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Originally Posted by roachboy View Post
it's better if you can ride without having to wonder if the guy in the car behind you is a sociopath, i find.
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Old 01-15-2009, 08:15 AM   #2 (permalink)
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Start here: Sun, Observation and eye damage - Wikipedia, the free encyclopedia

I found this interesting from that:
Quote:
Viewing the Sun through light-concentrating optics such as binoculars is very hazardous without an appropriate filter that blocks UV and substantially dims the sunlight. An attenuating (ND) filter might not filter UV and so is still dangerous. Unfiltered binoculars can deliver over 500 times as much energy to the retina as using the naked eye, killing retinal cells almost instantly (even though the power per unit area of image on the retina is the same, the heat cannot dissipate fast enough because the image is larger). Even brief glances at the midday Sun through unfiltered binoculars can cause permanent blindness.
I think what you're talking about, though, can lead to cataracts over the long-term. It's best to protect your eyes from extremities. The article says intense sun viewing can cause sunburn-like lesions in 100 seconds.
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Last edited by Baraka_Guru; 01-15-2009 at 08:18 AM..
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Old 01-15-2009, 11:14 AM   #3 (permalink)
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Also, in these times where there's a lot of snow, I would say it's best to have a pair of sunglasses handy, since all of that snow throws the light back at you.
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Old 01-18-2009, 06:48 AM   #4 (permalink)
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Sunlight through a magnifying glass can kill an ant or burn paper. Try it. Maybe without the ant.

Similarly... the lens of your eye focusses light on the retina, particularly the fovea (I think).

Don't look at the sun.
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Old 01-18-2009, 09:15 AM   #5 (permalink)
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You should wear your sunglasses when you sleep in the car, silly. Don't you have those awesome photochromatics?
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Old 01-18-2009, 11:11 AM   #6 (permalink)
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Hell with the binoculars, don't look at the sun for any length of time period. As someone who suffered from "welder's burn", I can tell you, it ain't worth it.
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Old 01-18-2009, 12:14 PM   #7 (permalink)
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Also, UV light can cause long-term damage to your eyes the same way it does to your skin. The effects are cumulative and don't require you to look at the sun; light reflected off snow, buildings, etc. still contains UV.
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Old 01-18-2009, 04:15 PM   #8 (permalink)
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I think the only solution is to get some Blue-Blockers. They're hot!
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Old 01-18-2009, 04:20 PM   #9 (permalink)
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I just got new glasses with Transitions lenses. They rock. It's my first time using them.

My problem is that I always wear my glasses, and so I seldom ever use sunglasses. I do wear a wide-brim hat in the summer, which blocks a majority of UV rays from your eyes. But now with the Transitions, I have protection year round, even in the winter. I highly recommend them.
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Humankind cannot bear very much reality.
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Old 01-19-2009, 05:13 PM   #10 (permalink)
Yarp.
 
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Thanks, all... I have no intentions with messing around with the sun and its rays. I do have a good pair of sunglasses that I paid enough for to warrant being extremely careful to not break/lose them. My vision's bad enough that I don't want to risk hurting it even more.
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Quote:
Originally Posted by roachboy View Post
it's better if you can ride without having to wonder if the guy in the car behind you is a sociopath, i find.
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