Ask Slashdot: How to Exploit Post-Cataract Ultraviolet Vision? 350
xmas2003 writes "I recently had cataract surgery with a Crystalens implant. With my cloudy yellowing (UV-filtering) natural lens removed, I see the world in a new light (more on that in a moment) as everything is brighter and colors are more vivid ... plus in focus.
As a typical Slashdot reader, I've been myopic since childhood, so it's wonderful not to have to wear glasses/contacts for distance. One interesting oddity is that I can now see ultraviolet light — it seems that there are a few people who have photoreceptors sensitive below 400nm into the UV spectrum. I've done some testing with a Black Light and UV filter to confirm this but would love to do more conclusive testing such as using a Monochromator — anyone in the Boulder, Colorado area have access to one? And any suggestions from Slashdot readers on how I can further explore this phenomenon? While I can't see dead people, I guess I have a 'superpower' ... although I'm not sure a middle-aged suburbanite dad should don purple tights and cape to become a crime-fighter!"
Re:Is there anything.. (Score:5, Informative)
Flowers are often more varied in the UV [naturfotograf.com] than in the standard visible light range.
No Capes! -- Edna Mode (Score:4, Informative)
No Capes! [youtube.com]
Re:First step (or post) (Score:5, Informative)
Ultragirl. I didn't even click the links yet, because I already know that only females are gifted with vision in or near the ultraviolet part of the spectrum.
although I'm not sure a middle-aged suburbanite dad should don purple tights and cape to become a crime-fighter!"
You need to take some remedial biology lessons, I think.
Aging does it (Score:4, Informative)
Re:First step (or post) (Score:2, Informative)
It isn't the lenses that detect ultravision. Nor, do the lenses pre-process photo stimuli. Nor, do the lenses send signals to the brain. It's the rods and cones at the back of the eyeball that detect, pre-process, then send signals along the optic nerve. Women who see anywhere near the ultraviolet have slightly different rods and cones at the back of the eye.
Baloroth was kind enough to provide a link, just a post or two down from here, which you might find informative. http://en.wikipedia.org/wiki/Tetrachromats#Possibility_of_human_tetrachromats [wikipedia.org]
Re:Dangerous (Score:5, Informative)
UV is a very wide spectrum. Near-UV isn't too scary.
UV-A (400-315 nm) is OK for short-term exposure. Your pupils won't constrict like they do for visible light, so keep the intensity low. Plain old blacklights are 350-400nm with the peak at 365nm, plus a small peak in the very bottom of the visible spectrum (which is the purple glow).
UV-B (315-280 nm) will probably be invisible, and it will do bad things to your eyes, so please stick to very low intensities if you want to fool with this. Read up on the risks first.
UV-C (280-100 nm) is utterly hostile to biology - the upper atmosphere filters this range out so life never evolved mechanisms to deal with it. Actually, UV-C is hostile to damn near everything: just from my own experience, it bleaches everything, and most plastics will degrade and become brittle with mere hours of exposure. I've test-fired a 185nm lamp in the open for a few seconds (wearing goggles!) and even across the room you can instantly smell ozone forming as it starts ripping oxygen apart. Stay away!
Re:First step (or post) (Score:5, Informative)
Before you go off calling someone a liar, maybe you should check up on it first. Google "see ultravilot". I just replied to another of your messages. I have a replacement lens in one eye, so I see both ways (normal and altered vision).
The following are quotes from http://www.guardian.co.uk/science/2002/may/30/medicalscience.research [guardian.co.uk]
Re:First step (or post) (Score:4, Informative)
No, but do natural lenses absorb UV?
Yes, and the extra type of rods she is talking about is _between_ the red and blue kind.. so all it does is allow greater differentiation of already seen colours, i.e. absolutely nothing to do with UV at all. So 2-3% of the female population can see a crazy amount of shades of colour.
The blue cells _can_ detect into the UV range, in both men and women, however normally this is blocked by the natural lens.
Re:First step (or post) (Score:5, Informative)
Not really; The paints are made from different materials which may or may not do the same thing in the ultraviolet range as the real objects he was painting.
Re:Dangerous (Score:4, Informative)
Brief glimpses won't hurt you at low power levels - this isn't a laser leaving a scorch track wherever it goes. The danger is in continuous exposure where your total absorbed dose accumulates to high levels.
365nm at a few watts is pretty low (but nonzero) risk. I work in a room with 300 watts of 365nm in the open every day and I don't really give it any thought when the lights click on.
Life has not evolved ways to deal with anything below about 300nm, which does not occur on the surface of the earth. 254nm is what they use for germicidal lamps. It kills bacteria by causing massive DNA damage... Consider that. Your skin is a little more resilient, but like sun exposure, it will result in sunburn if you blast yourself with a high dose, and over time it causes skin aging and eventually cancer. On your eyes you're running the risk of cataracts.
On the upside: your glasses almost certainly block 254nm. Pretty much everything does - the bulbs and any windows are made of fused quartz which is one of very few things that will pass 254nm. It also doesn't tend to reflect around as much as visible light. Even shiny aluminum surfaces will absorb most of it. Silver mirrors reflect it as long as it's first-surface reflections; glass in front will absorb it. So perhaps you're not getting that much exposure except when you reach under the lamp. You can measure it with a radiometer if you have one handy to see how much is really being reflected toward you.
My suggestion: I always use glasses regardless of exposure. For your skin, it kind of depends how you use it. If you flip the lights on for a minute to examine a sample and then turn them off, and you're only reaching under the light for a few seconds, it might be OK to accept (but not ignore!) the skin risks. If you're leaving samples to react under the lights for hours at a time, I'd suggest you go down to Tap Plastics and buy a sheet of polycarbonate - it's what they use in UV safety goggles, and it's completely opaque to UV. Attach it to the front of the bench, and just reach around when you have to prod your sample.
Re:Dangerous (Score:5, Informative)
Fortunately we were all living underwater back then. Before the Oxygen Catastrophe we were really damn deep where there's no light at any wavelength. Even the green things stayed well under the surface until the ozone layer was established.
Nothing has ever lived in the presence of UVC. There are few absolutes in biology, and I certainly want my readers to consider the implications of that before they go experimenting with short wavelengths: life evolves to fill any niche it can, but it has never gone there, and neither should you.
Re:First step (or post) (Score:4, Informative)
These women just say "pfffrrt I can seen all colours, even ultraviolet!"
To which the researchers tried to explain how that's unlikely and would try to run some tests..
As suddenly the women says "Is it me, or is it getting hot inhere ?" while there's some 70s funkmusic that comes from her bra, which is bulging...
As the scientist tries to remain his posture, and tries to convince the woman with all spectrum vision he needs to investigate her claims.. she replies "Investigate this.... doctor..." while she pushes her boobs in his face and scientists view is blurred and limited to only a few spectrums... While making up his results out of shame to write down his actual personal findings.
This is generally how women partake in research.