How occurrence Color Blind

Color blindness is a general term for disorders of color perception. Difficulty distinguishing color blind or blind to shades of a particular color. Color blindness can not be cured. According to statistics, approximately 9% of men and 0.5% of women bearing the color blind. Their problem is particularly distinguish shades of green (deuteranomali) or shades of red (protanomali) and green color blindness (deuteranopia) or red (protanopia). Difficulties or blindness to the color blue and the total color blindness is rare.

Why is this happening?

1. The absence of cone cells

Retina has nearly seven million photoreceptor cells consist of two types of stem cells and cone cells are concentrated in the middle, which is called the macula. Stem cells are very sensitive to light, and can capture weak light like the light of the stars at night, but that it can not distinguish colors. Thanks to stem cells we can see the things around us at night, but only in shades of black, gray, and white. Cones can see the details more detailed objects and distinguish colors but only react to bright light. Both types of cells are complementary functions so that we can have sharp eyesight, detailed, and colorful.

There are three types of cone cells in the retina. They each contain a visual pigment (opsin) that react to different wavelengths of light are different: red, green and blue. Cone cells capture light waves according to their pigment and pass them in the form of electrical signal transmission to the brain. The brain then processes the signals and combining red, green and blue color impressions from the retina to the specific. Because of differences in the intensity of each of the basic colors, we can distinguish millions of colors. Reception interference of light on one or more types of cone cells in the retina have a direct impact on color perception in the brain. Color-blind person who has a disability or lack of one or more types of cone cells.

2. Genetic disorders

Color blindness is inherited abnormality. Because the gene for red and green visual pigment found on the X chromosome, red or green color blindness usually occurs in males. Unlike women, men have only one X chromosome so that there is no backup copy that can replace defective genes are appropriate. A woman must have a defect in both the X-chromosome to be red or green color blind. When that happened, her son would also color blind, because he inherits an X chromosome from his mother. In addition to its offspring, a mild form of color blindness is also caused by mutations in the opsin gene on the X chromosome

Brain injury or stroke can interfere with color processing in the brain. If the new color blindness occurs in adolescence or adulthood, the cause is disease in the macula, such as macular degeneration or optic nerve damage in its wake.