Colour perception is the ability of the eye to differentiate colours. A simple test with the Ishihara's test will detect red-green colour deficiencies commonly known as colour-blindness.
Colour blindness is typically an inherited genetic disorder, with males more commonly affected than females. Occasionally, acquired causes like disease, drugs and chemicals may cause it.
There is no known cure, but diagnosis can alert the person to make certain adaptations and avoid certain occupations which require precise colour differentiation.