Pathogenesis (development of disease)
Two types of light-sensitive cells are found on the retina. Rods are responsible for twilight and night vision. Rods are significantly more sensitive to light than cones. Cones mediate day vision, color vision, and resolving power. Red, green and blue cones can be distinguished.
In color vision impairment, the sensitivity of the cones to certain colors is reduced. However, the sensory cells (cones) are present in sufficient numbers. In color blindness, some of the sensory cells (cones) are missing. Depending on the color blindness, the green, red or blue cones are missing.
Congenital color vision disorders are inherited X-linked and therefore occur predominantly in males.
Color vision disorders include:
- Achromatopsia or achondroplasia – total color blindness, i.e., no colors can be perceived, but only contrasts (light-dark)
- Deuteranomalie (green weakness; green cones degenerated).
- Deuteranopia (green blindness; green cones absent).
- Acquired color vision disorders
- Complete color blindness
- Protanomaly (red deficiency; red cone degeneration).
- Protanopia (red blindness; red cones absent).
- Tritanomaly (blue-yellow weakness).
- Tritanopia (blue blindness; blue cones absent).
Etiology (causes)
Biographical causes
- Genetic burden from parents, grandparents.
Disease-related causes
Eyes and eye appendages (H00-H59).
- Pressure effect on the optic nerve, unspecified.
- Macular degeneration – group of eye diseases that affect the macula lutea (“point of sharpest vision”; yellow spot) of the retina and are associated with a gradual loss of function of the tissues located there
- Stargardt’s disease – hereditary form of macular degeneration.
- Optic atrophy – atrophy of the optic nerve.
Neoplasms – tumor diseases (C00-D48)
- Tumors of the eye/brain, unspecified.
Injuries, poisoning, and other sequelae of external causes (S00-T98).
- Intoxications (poisonings), unspecified.
