(or color blindness) one of the varieties of colour vision in humans and animals that is characterized by insensitivity to certain colors (in rare cases, all). Mostly the blindness affected men (about 10%) and is practically unaffected women (less than 1%). Color blindness is most often congenital, it is inherited to the next generation or a generation. Rare cases of acquired color blindness.
A healthy person sees the whole spectrum of colors thanks to the light-sensitive cone cells contain the photosensitive protein pigment that is responsible for the perception of colors (red, blue, green). The color blind one or more protein pigments are absent or are damaged. In this case, the person has abnormal color perception does not perceive certain shades. Color perception occurs according to the degree of brightness, colorblind defines colors according to their belonging to a warm or cold tones.
Generally accepted is the division of color blindness 3 types
- deuteranopia impaired perception of the green segment of the spectrum
- Protanopia impaired perception of the red segment of the spectrum
- tritanopia is a rare form of color blindness, which is characterized by impaired perception of the violet segment of the spectrum.
Inheritance of color blindness in almost all cases, occurs from mother to son, rarely the father is colorblind can pass his daughter’s inability to perceive certain colors. This happens only if the mother is also broken by the ability. This is because the female X chromosome contains a recessive gene (which she develops), is responsible for blindness. At the same time, the male Y-chromosome does not contain this gene at all, therefore does not determine the perception of colors.
Despite the fact that the gene for color blindness is contained in the DNA of women, it does not affect her ability to perceive colors. The man who received the gene from the mother, is likely to be color blind 11.
Blindness in children and adults may be purchased. The reasons of its development can be
- disease of the optic nerve
- of retinal diseases
- disorders in the Central nervous system
- getting chemical substances into the body.
Signs of color blindness in each case manifest themselves individually, but the overall clinical picture of this phenomenon include these symptoms
- non-perception of green and red colors
- non-perception of blue and green colors
- diachrome (black and white) perception of the world
- low visual acuity
- nystagmus (involuntary reusable closure of the eyes).
Testing for color blindness is to pass specific tests that determine a person’s ability to respond to the full spectrum of colors.
Ishihara test detects visual defects and allows you to accurately assess the level of color blindness. It is a table with colorful spots of different colors. Abbreviated test 24 table designed for medical professionals, employment agencies, municipal institutions and employees of those industries where a high level of view of one of the criteria of efficiency, such as the work of the pilot or driver. Full test developed exclusively for
to determine the degree of color blindness.
Color blind test Rabkin polychromatic test, which consists of 27 tables. Each table is formed of small circles and dots of different shades of the same color together they form a figure (number, symbol). Colorblind this figure can not see, but a person with normal color perception will notice right away.
Today in the world of medical practice colorblindness recessive treatment can not be. This is due to the genetic cause of color blindness.
Treatment of acquired color-blindness is possible, but it does not guarantee full recovery of color perception. There are methods of correction of color blindness
- glasses that block bright light make it easy to distinguish colors
- painted glasses, contact lenses improve color perception, at the same time, they visually distort the objects.