Briefly looking at the sun / LED flashlights - Permanent Vision Damage?
11-30-2008, 04:11 PM
#1
Gets Weekends Off
Thread Starter
Joined APC: Apr 2007
Posts: 456
Briefly looking at the sun / LED flashlights - Permanent Vision Damage?
If your vision is already "Day adjusted" can looking at the sun for even like .25 of a second then looking away cause any permanent damage to vision?
What about really bright flash lights/or the new LED types...
How can you tell if your eye has any bright light related damage?(Aside from going to the eye doctor) Is it safe to assume that if you have 20/20 vision then you probably didn't damage your eyes by the sun or bright lights?
Thanks
What about really bright flash lights/or the new LED types...
How can you tell if your eye has any bright light related damage?(Aside from going to the eye doctor) Is it safe to assume that if you have 20/20 vision then you probably didn't damage your eyes by the sun or bright lights?
Thanks
12-01-2008, 06:03 AM
#2
Prime Minister/Moderator
Joined APC: Jan 2006
Position: Engines Turn Or People Swim
Posts: 39,297
No flashlight is going to be powerful enough to harm your eyes (obviously they can ruin your dark-adaption). To do immediate permanent damage would require a powerful laser of a nuclear fireball. The retina can get sunburned by exposure to reflected sunlight from snow, but that will recover in a few days (painfully).
But it is not safe too look directly into the sun for ANY length of time. The sun produces a tremendous amount of UV light which can result in long term damage to your cornea and retina. Of course we all glance at it occassionally, but try to avoid it. Same with a welding torch...massive UV source, never look at one without a welding shield.
Even if the sun is dim (clouds, haze, etc) or below the horizon the UV can still be at almost full strength. It doesn't get blocked by moisture like visible light, which is why you can get sunburned on a cloudy day. At sunset (and sunrise) UV refracts differently than visible light...just because the visible disc is below the horizon does not mean that you are not getting massive UV..enjoy the sunset, but don't look directly at the disc.
But it is not safe too look directly into the sun for ANY length of time. The sun produces a tremendous amount of UV light which can result in long term damage to your cornea and retina. Of course we all glance at it occassionally, but try to avoid it. Same with a welding torch...massive UV source, never look at one without a welding shield.
Even if the sun is dim (clouds, haze, etc) or below the horizon the UV can still be at almost full strength. It doesn't get blocked by moisture like visible light, which is why you can get sunburned on a cloudy day. At sunset (and sunrise) UV refracts differently than visible light...just because the visible disc is below the horizon does not mean that you are not getting massive UV..enjoy the sunset, but don't look directly at the disc.
12-01-2008, 06:11 AM
#3
Gets Weekends Off
Joined APC: Jan 2008
Position: the correct seat
Posts: 1,422
It's not a really bright idea to go looking at the sun. Especially as a pilot, one should try to avoid it. There's a reason your reflexes make you squint when you look into a bright light.
However, if you must, I believe there is a certain kind of tinted lens that can be used to safely observe a solar eclipse. I don't recall what it's called, but you can probably try to find it on the NASA website. If you're going to make a habit of it though, I'd schedule a quick chat with an ophthalmologist, and be sure to indicate that you're a pilot.
I have no clue about the vision acuity thing. If you're worried about it, I don't think that an accidental glance is going to do any permanent damage, but I'd suggest seeing an ophthalmologist if you think you have experienced any change in your vision.
However, if you must, I believe there is a certain kind of tinted lens that can be used to safely observe a solar eclipse. I don't recall what it's called, but you can probably try to find it on the NASA website. If you're going to make a habit of it though, I'd schedule a quick chat with an ophthalmologist, and be sure to indicate that you're a pilot.
I have no clue about the vision acuity thing. If you're worried about it, I don't think that an accidental glance is going to do any permanent damage, but I'd suggest seeing an ophthalmologist if you think you have experienced any change in your vision.
