What is color blindness?

Color vision disorder when the ability to percept color tones is disabled is known as color blindness. The name color blindness is usually not absolutely precise because the most of affected patients in not able to perceive only certain color what means that they have color vision to some extent. In the case of total color blindness they do not distinguish any color and perceive surrounding world only as black-and-white with different levels of brightness. Color blind people comprise not even 1% of the entire population and the rest can be labeled as color mistaken.

Color blindness can be partial and in that case colors are perceived differently and inaccurately in comparison with a person with average color sense. It depends on which color out of three basic ones is perceived incorrectly.

Congenital disorder of color sense is a matter of genetics and is inherited recessively. Congenital disorders of color sense are fixed on the X chromosome. Men have only one X chromosome and so it is not possible to compensate its eventual malfunction with the genetic information from other chromosome as it is the case for women. They suffer from the disorder only when this defect occurs on both chromosomes. Women are usually only transmitters of the color sense disorder.

Color blindness occurs approximately in 8.5 % of the entire population out of which men account for 8% and women for only 0.5%. The number of disorders also varies as far as different races are concerned what is caused by predisposition for genetic disorder of the X chromosome. The results of surveys show that the disorders of color sense are most common to white men. The lowest occurrence of congenital disorders of color perception was found to be among black race.