There are many types of color blindness. The most common are hereditary (genetic) photoreceptor disorders, but it is also possible to acquire color blindness through damage to the retina, optic nerve, or higher brain areas. Higher brain areas implicated in color processing include the parvocellular pathway of the lateral geniculate nucleus of the thalamus, and visual area V4 of the visual cortex. Acquired color blindness is generally unlike the more typical genetic disorders. For example, it is possible to acquire color blindness only in a portion of the visual field but maintain normal color vision elsewhere. Some forms of acquired color blindness are reversible. Transient color blindness also occurs (very rarely) in the aura of some migraine sufferers. The different kinds of inherited color blindness result from partial or complete loss of function of one or more of the different cone systems. When one cone system is compromised, dichromacy results. The most frequent forms of human color blindness result from problems with either the middle or long wavelength sensitive cone systems, and involve difficulties in discriminating reds, yellows, and greens from one another. They are collectively referred to as "red-green color blindness", though the term is an over-simplification and somewhat misleading. Other forms of color blindness are much rarer. They include problems in discriminating blues from yellows, and the rarest forms of all, complete color blindness or monochromacy, where one cannot distinguish any color from grey, as in a black-and-white movie or photograph

colorblindness is usually passed on from the X chromosome and that is why it is passed on to men more easily because they don't have 2 X chromosomes to take over for the messed up trait! I think it is Red and Green usually not being able to be seen, but there are different types of colorblindness so..could be many!

Color blindness is no big deal... what real life situations would it cause you problems with? "Waaaaah, I can't tell if this tomato is ripe" and "Help, I've dropped my green pepper on the lawn and can't find it!" are the only two I can think of...

I am personally red/green color blind. It's not that I can see the color, it's that I have a hard time telling the difference between some of them. I have the hardest time when it is a dark or light shade of a color, or is a mix of a color. Pure, bright colors don't give me much trouble. It can be a pain and sometimes embarrassing, but it hasn't had a big impact on my wife except for my wife always telling the story about how my clothes didn't match on our first date. A funny story though. My wife's roommate when we were dating was fascinated with this and always would ask me "What color is this?" on various things. One day she came out and asked me "So did you just...not learn your colors?" I told her that was it, I didn't have time to do it while I was getting my engineering degree.