Extrasensory Perception: A Hypothetical Case for Rare Females on Submarines
Did the military ever test you for color blindness? The condition disqualified many from duties in which practical limitations were predictable and potentially grave.
Would any submariner want a color blind Magellan interpreting his boat's navigation charts?
Color blindness is usually considered a disability. In some situations, however, color blind people have advantages over those with normal color vision. Color blind individuals are better at detecting certain camouflages, for instance. In WWII it was discovered that analysis of color aerial photos yielded greater information when at least one analysis team member was color blind. From an evolutionary perspective, hunting groups including a color blind hunter (one in twenty) could probably spot prey others cannot.
Monochromats may have a minor advantage during the first five and a half minutes of dark adaptation. Are you thinking of Rig for Red situations? What about low-light, submarine damage control?
Only two percent of females are color blind (Sewell, 1983) versus eight percent of males since the latter are at greater risk of inheriting an X linked mutation in their single X chromosome.
For a few women it may be possible to have four different types of retinal cones. Such rare women are tetrachromats, since they require a mixture of four spectral lights to match an arbitrary light. This means they may be able to see wavelengths beyond those of a typical human being's eyesight, and may be able to distinguish colors that to a human are identical.
Humans and closely related primates normally have three types of retinal cone cells and are therefore trichromatic. However, at low light intensities rod cells can contribute to color vision, giving a small region of tetrachromacy in color space. One study suggested that 2–3% of the world's women might have the kind of fourth cone that lies between the standard red and green cones, giving, theoretically, a significant increase in color differentiation.
Having a tetrachromatic female on a submarine would impart powers of a nature previously ascribed to such fictional characters as Mr. Spock. My guess is that tetrachromatic females can be seen in full color spectrum only by one another.
7 March 2007 - independent.co.uk - SEEING BENEATH THE SEA
Because light behaves differently in water and air, land-adapted human vision is lousy in water. Someone, however, forgot to tell the Moken - gypsies who ply the Burmese archipelago and Thailand's western coast. Moken children, who spend days diving for clams and sea cucumbers, can see twice as much fine detail under-water as European children. While the pupils of the latter expand underwater, in response to the dimness of the light, Moken pupils shrink to their smallest possible diameter, improving acuity underwater. Mokens also use the lenses of their eyes more, squishing them to the limit of human performance.
Does anyone yet have a photo (drawings do not count) of either the hypothetical, tetrochromatic human female, or the shabbily documented (but still unphotographed) Abyssobrotula galatheae? Just a thought.
YouTube for color blind and teratchromatics only (the rest may be disappointed, and 3-D glasses will not help, Mad Dog):
If color blind, what did you see?... Everyone else sees lots of red camouflage.