The colorblind thread got me wondering about the opposite effect: Have there been any documented cases of people being able to see outside the regular visible spectrum, perhaps further into the infrared or ultraviolet ranges?
It’s possible, but it’s never been documented.
People with aphakia may be able to see near UV:
I also ran across this, but don’t know anything else about it:
Here’s a good article on Aphakia:
Yes, but it wouldn’t be a different sensation than just seeing violet. A hypothetical tetrachromat, on the other hand, would not be able to see any light that normal folks can’t, but would see it differently: Two different visible light spectra which look indistinguishable to normal humans would be distinguishable to a tetrachromat.
I have talked to freinds that insist that on a double rainbow, bewteen the two “Violets” they can see a faint purplish-greenish band.
I started a thread on this several months ago, but I’m too lazy now to find it. I’ve seen her pick out an extra line on a hydrogen lamp run through a dispersion grating that no one else saw. At the same time she can’t do shit for colorometric titrations, which I have a sneaking suspicion might be related. (either that or she just uses that as an excuse to get out of doing those tests:D)
Are they maybe talking about Alexander’s dark band?
Nah, I’m pretty sure that’s Octarine. Which means his friends are wizards, or cats. Or both.
This guy, linked in the Wikipedia article referenced by Chronos, claims that the human retina has four colour-sensing systems (not sure if they’re cells or what)–‘red’, ‘green’, ‘blue’, and ‘ultraviolet’–but that the lens of the eye blocks the ultraviolet. He’s postulated an additional axis on the colour model, making it a 3-D space before saturation or intensity is considered.
From that article I linked, they have this to say on what it looks like:
That’s just the bestest band what am, honey lamb.
How would a person know that he is seeing into the IR or UV spectra? In daily life, that is, without looking at a special image or device meant to discern that.
You might be interested in the subject of tetrachromat http://www.post-gazette.com/pg/06256/721190-114.stm which allows some people to see more colors
Just a comment that I find the title of this thread misleading. The answers suggest some people might indeed see into the ultraviolet or IR range, but they are perceiving that light as normal colors, and not as some some wild and crazy new type of colors. But that would be cool.
Aside from anomalous situations (such as getting reflections of the sun from odd surfaces), there shouldn’t be anything between the primary and secondary rainbows – Even most ordinary scattered light is directed away from that region. That’s the cause of the “Alexander’s Dark Band” mentioned above. The ibfrared rainbow does extend into that region, and has been imaged on infrared film (and, no doubt, with IR cameras). Possibly your friend is suggesting that he could see the IR bow, but that’s incredibly highly unlikely.
The dark band between the two rainbows is bounded not by the violet end of the rainbows, but the red end. If your friend truly saw sometrhing in the space between, he’d have said he saw it between the reds, not the violets. This makes me suspect that your friend is mistaken about what constitutes a “double rainbow”, because there IS a phenomenon that takes place at the violet end of the rainbow. It’s the supernumerary rainbow, which you can see if the sun is bright and your raindrops are pretty consistent in size, and are fairly large. In fact, you can often see several supernumerary rainbows, alternating pink-purple and blue-green in color.
This picture shows a double rainbow (with Alexander’s Dark Band). If you look inside the smaller Primatry rainbow you can see several supernumerary bows:
http://www.jal.cc.il.us/~mikolajsawicki/rainbows.htm
Here’s a better picture of supernumerary bows:
Well, I think it’s unfair to criticize the thread title. The answer to that title is “No.” Kind of a boring thread. We’re making the best of it.
Post-cataract surgery, many people notice that the world looks different, and they can see certain things (patterns on wildlife, flowers, etc.) that are discernible in UV but not visible light.
See Nectar Guides.
The fellow in the one story I linked above had only one of his lenses removed, so he has UV vision in one eye and normal vision in the other.