How Many People Are Colour-blind?

Colour blindness is a condition, where the sufferer has diminished ability to perceive differences in colours. Colour blindness is almost never a complete absence of colour vision, where an individual is only able to see shades of grey. Red/green colour blindness is the most common form, attributing to 99 percent of the cases and it is most commonly an inherited condition. There is no treatment for colour blindness, nor is it usually the cause of any significant disability. However it can be frustrating to individuals affected by it. About 8 percent of males have some level of colour blindness and for female the corresponding percentage is 0.4. Colour blindness is diagnosed with the Ishihara colour test, which consists of a series of pictures of coloured spots. The test is most often used to diagnose red/green colour deficiencies. A figure of one or more Arabic digits is embedded in the picture as a number of spots in a slightly different colour and can bee seen with a normal colour vision, but not with a colour defect.

Color Blindness is more often than not an inherited condition, which causes the sufferer to be unable to distinguish certain colors.
More numbers of people suffer from red/green color blindness, and statistics show that this form of color blindness aflicts about 99 percent of people with the condition.
Another form of color blindness is blue/yellow, but this is quite uncommon, and there is no test available for it.
Amazingly, color blindness occurs in about 8 to 12 percent of people of European origin, and affects only about one half of 1 percent  of females.
Complete color blindness, that is, a person being able to see only in shades of gray is very rare.
There is no known cure for color blindness, although some sufferers are quite disabled and irritated by it. These people find that they cannot read weather forecasts, nor can they read traffic signals.  Others just find it slightly irritating.