h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I just quickly googled it, and the paper I saw showed curves for the transmittance of the human lens and cornea being lower at lower wavelengths, so this also suggests IR.

That kind of makes me want to replace my lens, just so I can get nightvision.

My night vision's pretty good. S'all to do with a reliance on the rods rather than the (colour) cones.

Hence why I confuse colours not by hue (which I can't see) but by brightness and why in very little light adjust to contrast of light and dark better.

Often when I can't sleep I'll come down at night to and not bother switching on the lights. I can see just fine.

I'm also pretty good at spotting certain camouflages.

Oliver Sacks did a book called the island of the colourblind which discusses an isolated island population of colourblind people who tend to do a lot of their fishing at night.

>>"There´s a condition where people have an extra colour receptor in their eyes, I imagine such people see different colours than most."

Possibly, unless it gave some particular advantage, it could be more annoying than useful to see mismatches that most people can't see.

Imagine being a rare trichromat in a world where most people only saw in two colours, including decorators, graphic artists, fabric designers, etc, and where dyes/pigments were chosen purely on their 'colour' on a one-dimensional scale.

That reminds me I was going to write a reply to that. I looked into tetrachromacy a few years ago, and the state of research at that time suggested there was very little evidence for 'functional' tetrachromacy. It's known on the basis of genetic analysis that about 8% of women (IIRC) have four types of colour receptor (and no men, sorry guys), but as far as I know, only one subject at all is known who passes the 4D colour test. The reason for this is probably that the fourth colour receptor is in most cases very, very similar to an existing one (I can't remember if it's the low or high wavelength receptors that are duplicated). Another interesting fact is that for women who do have four colour receptors, if they have children who are boys, it's very likely that they will have some sort of colour blindness.

>>> an isolated island population of colourblind people who tend to do a lot of their fishing at night.

I have color vision and I'd very happily fish at night if it weren't for the sizable citation the fish & game warden would pin on me. Night fishing is easy pickings, too easy, that's why it's against the law.

Perhaps the phenomenon of night-fishing should be attributed to an absence of wardens patrolling that island rather than the presence of color-blindness. Bet that wouldn't sell any books though.


HN

I remember one of the early answers to this thread was about the difficulties in finding out what colour dinosaurs were. Someone seems to have found out now:

http://news.nationalgeographic.com/news/2010/01/100127-dinosaurs-color-feathers-science/