<P> Color blindness always pertains to the cone photoreceptors in retinas, as the cones are capable of detecting the color frequencies of light . </P> <P> About 8 percent of males, and 0.6 percent of females, are red - green color blind in some way or another, whether it is one color, a color combination, or another mutation . The reason males are at a greater risk of inheriting an X linked mutation is that males only have one X chromosome (XY, with the Y chromosome carrying altogether different genes than the X chromosome), and females have two (XX); if a woman inherits a normal X chromosome in addition to the one that carries the mutation, she will not display the mutation . Men do not have a second X chromosome to override the chromosome that carries the mutation . If 8% of variants of a given gene are defective, the probability of a single copy being defective is 8%, but the probability that two copies are both defective is 0.08 × 0.08 = 0.0064, or just 0.64% . </P> <P> Other causes of color blindness include brain or retinal damage caused by shaken baby syndrome, accidents and other trauma which produce swelling of the brain in the occipital lobe, and damage to the retina caused by exposure to ultraviolet light (10--300 nm). Damage often presents itself later on in life . </P> <P> Color blindness may also present itself in the spectrum of degenerative diseases of the eye, such as age - related macular degeneration, and as part of the retinal damage caused by diabetes . Another factor that may affect color blindness includes a deficiency in Vitamin A . </P>

What does color discrimination of red/green mean