Color-blind people pick up chromatic differences invisible to others

A group of researchers at the University of Cambridge and Newcastle- upon-Tyne, Great Britain, have discovered that color-blind people are able to pick up gradations that are invisible to people without this vision deficiency.

The research appeared in the magazine Cell Biology, and is based on a direct comparison between one group of subjects with red-green deficiency, deuteranomaly, and another with normal vision.

Those who cannot distinguish between green and red can, however, pick up very subtle gradations in the color khaki, which others are unable to see.

Around 6% of men have deuteranomaly. The genetic mutation that affects one of the three pigments in the retina's cells which are responsible for color differentiation, is linked to the X chromosome. The percentage of women who suffer from deuteranomaly is lower because they have two X chromosomes. After mutation, the pigments respond to red and green in the same way and this is why color differentiation is lost.