In the GD discussion on a glow in the dark bunny, I got to thinking about how bizaare it is to have a form of EM that is completely absorbed by our surroundings, but that we can’t see (well, we can “see” it, but only as a side effect as electrons drop back down, releasing a quanta of visible light).
Now, while UV can be bad for us (cause sunburns, cataracts) it normally takes a while to act, and in the case of normal light, our eyes squint in reaction, which helps a lot.
Now I’ve heard that sunglasses that don’t properly filter UV can make things worse. A person doesn’t realise their eyes are getting fried.
Is that the case?
Let’s say I was a trespasser breaking into a sadistic person’s house. They have the premises illuminated to an incredibly high intensity with UV. I notice perhaps that I and some of my surroundings are glowing, but would my eyes react? Would they feel hurt? Would I squint? Could it cause any harm at all?
The only thing I’m fairly certain it wouldn’t do is reduce my regular vision, since a blinding light is simply overstimulation, and my rods n cones aren’t being stimulated, are they?
Optics workers have been hit by this – If you use far UV it won’t even be transmitted by the cornea (the trick with going dep into the ultraviolet is to find matrials that will even tansmit your light – glass or plastic will block virtually everything below 3000 Angstroms. So will your cornea). It il be absorbed by your cornea and you’ll end up with a good sunburn on your eyes. One of my advisors had this happen to him. After a little while it felt as if there was sand under his eyelids (due to raised “blisters” on the eye itself). This would drive me nuts, although I’m told that, as you heal, yoyu see pretty rainbow-colored interference rings around everything.
Too much UV and you’ll get a second, then a third degree burn. Not good.And I think you’d feel it immediately.
But since the light isn’t even getting to your cones and rods you wouldn’t be subjected to overstimulation.
I suspect you’d have this problem with very6 bright white light. Tom Clancy seems to be describing this kind of thing in his book “Debt of Honor”. The thing is hat extremely bright sources (especially lasers) can scar the retina, destroying cones and rods. This will certainly reduce your regular vision. At some places I’ve worked they inspected your retina to see if you’d caught a laser beam on the retina and lost vision. I understand that some people have lost segments of retina this way.
And then there are the laser deliberately built as battlefield blinding devices. These are an abomination unto God and Man.
Thanks for the detailed Engineer’s response.
As for the above though, I dunno, personally I’d prefer to be blinded then say, sliced n dice by anti-personel mines, or killed.
And with the current announcement of successfuly restoration of optic nerves (possibly retinas could be done too? they are using stem cells) at least I’d have hope of regaining sight.
In any case, living without sight is better then being dead. It seems that ending a war by striking the enemy blind with high precision lasers is a lot more humane then bombing strikes.
I’ve heard the same argument about the “humanity” of using blinding weapons before (I’ve been in engineering meetings where these lasers have been discussed as agenda items), and it always gives me the willies. Deliberately blinding people seems to me beyond the pale – and I think those possible “fixes” you describe are a LONG way off, even giving technology its proper due.
I don’t think it really is a “choice” between being chopped up and being blinded. In the Clausewitzian “Fog of War” people will be blinded, THEN chopped up when they can’t see to avoid the mined regions.
I’m still hauinted by all those WWI images of mustard-gassed soldiers, blinded, leading each other out of he battlefield. It’s one of the most chilling images from that inhuman war, and I think it spooked both sides enough to keep it out of WWII. (I know that gas was notoriously unreliable, depending o shifts of win and all. But I don’t think that’s the whole story of its nonuse later.)
Ever notice that you can’t look directly at a black light without your eyes reacting as though you’re staring directly at the sun? Even though black lights don’t seem to give off much visible light (they don’t light up the room), it sure does make your eye lids want to slam shut. I’m sure my nervous system is trying to tell me something (“don’t stare at that, you dolt!”).
Well, when they do give off visible light, they don’t give off much of it.
The evil security system would still work - the intruder, even a UV aware one, might not know to avoid the dimly glowing purple lights, or whatever color they’d be. Still not certain if your eyes would try to close when looking at that either. Opus says yes - I’ll have to dig out my blacklight bulb at home. Thing is, that one generates a lot more visible light then it should - I might be squinting just because of the brightly glowing filament.
You could g the other way, into the Infrared and beyond. But you start running into he same problems – light absorbed in the first layers it encounters, the cornea, etc, so it never gets to the retina.
Of course, as far as I’m concerned that’s a good thing.
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