Re:Hacker changes the way people with colour blindness see t...
by extension on Saturday December 18, 2010 @11:43AM
(#2019705)
Except we don't perceive the dimensions of color as comprehensively as we perceive multi-dimensional space. We can intuitively construct straight lines, planes, spheres, cubes and various other geometric primitives. We can't construct those things in color space without a lot of specialized knowledge.
We basically perceive colors as similar or not, as well as a few basic attributes like brightness and saturation. If we're missing a dimension, we just can't differentiate between as many colors as other people. This is why people can go their entire lives without realizing they are colorblind.
So, if you can compress the normal range of colors into the range that can be seen by someone with partial colorblindness, it could potentially make all the difference.
Note also that magenta exists as a color (ie unique subjective experience), even though no monochromatic light can evoke it
I don't think any light can evoke it, right? You would have to artificially stimulate the optic nerve to see it.
tl;dr - color is a 3D space. Colorblind people can only percieve two of these. This device may change the projection of the 3D space on their 2D space, but it will not magically make the third dimension pop out.
-- original post, a bit less synthetic.
Color is a 3D space (wherever you chose to put the axes, RGB, HSL...) because we have three subtypes of color-related light detectors, called cones, in our retina (there are more photosensitive cells, but they aren't involved in color).
Each cone is sensitive to a range of the visible spectrum, with peak sensitivity respectively in what we call red, green and blue. These ranges are overlapping, though, which allows our brain to interpret monochromatic light correctly by weighting the response of each type of cone.
See [1] for a schema and a more thorough explanation.
Note also that magenta exists as a color (ie unique subjective experience), even though no monochromatic light can evoke it. You get it by stimulating the red and the blue cones, sparring the green one.
All of this to say that with two cones, you're stuck in a 2D space of color blindness.
This tool may help colorblind people to get a different projection of the 3D space in their 2D detection field, but they will not be able to perceive the 3D space at once.
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For those who didn't get their dose of photoreceptors trivia:
The retina also contains another type of detectors called rods, which are much more sensitive to light than the cones, and is involved in both day and night vision whereas the cones are only stimulated in daylight This explains why you don't percieve colors in the darkness.
At last, the recently discovered melanopsin containing ganglion cells are involved in the circadian cycle and other light-related acivity in the autonomous nevous system.
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[1] http://www.unm.edu/~toolson/human_cone_response.htm