I was diagnosed with color blindness as a child. I was told I was red-green color blind. However, this never made much sense to me, because I can tell the difference between red and green ... or can I?
OK, yes, I can. But reds seem duller to me. I have what is sometimes called "red weakness." There are three basic photopigments (colors) we humans see: red, green, and blue. People with normal sight are trichromats, whereas people we normally think of as color blind are monochromats: they see no pigment at all, or only one color (usually blue, the shortest wavelength).
Then there's dichromats, who cannot see one of the three wavelengths. I'm a trichromat like most people, but an anomalous one. Specifically, I am protoanomalous trichromat, which means my red photoreceptors are abnormal.
This explains some of why my wife says I can't tell the difference between various colors, but she thought it was all in my mind, because I can tell the difference between red and green, despite my story about what the doctor told me when I was a kid. I showed her two pictures, showing what a normal person sees, and what someone like me sees. My problem isn't very acute, and I can see the number "2" in the normal picture, but I have to strain for it. I can see some difference between the two pictures, but it is very slight. My wife sees a significant difference between the two.
(BTW, I got these pictures from a web site that created them using a color filter from wickline.)
If they designed those test-your-color-vision pictures instead of mere humans, we'd all fail their tetrachromat tests. They'd laugh at us. Little chirpy laughs. Full of pity and condescension at our inability to look at a flower and see the "FREE POLLEN HERE" sign in ultrapurple.
Re:I for one, welcome the rule of our avian master
rafael on 2004-09-05T18:53:04
I remember having read an article somewhere about tetrachromats detected in the human population. Without linguistic support, they were unable to think about the extra colours they were seeing. As a dichromat, I find the interaction between languages and colour perception fascinating.Re:I for one, welcome the rule of our avian master
ziggy on 2004-09-07T03:10:26
I remember reading something about that a year or so ago.IIRC, tetrachromatism in humans is almost exclusively a female trait, much like all forms of color blindness is almost exclusively a male trait. The difference between avian tetrachromatism and human tetrachromatism is that people with the trait do not have ultraviolet color receptors, but have two sets of green (?) color receptors, so they can more finely distinguish colors in the middle of the human-visible spectrum. (I think one test was to tell the difference between two subtly different shades of yellow.)
Re:I for one, welcome the rule of our avian master
rafael on 2004-09-07T07:19:14
We probably read the same blogs:) I wonder what evolutionary advantages tetrachromatism would bring to humans. It is a very probable hypothese that perception of colours becomes more accurate through centuries (studying the vocabulary colours in ancient indo-european languages confirms this.)
Re:Clothes
cog on 2004-09-06T10:30:55
Isn't Zatôichi a blind samurai?Yeah... he'd probably regret it, alright
:-)
