The human eye is able to distinguish three different colors – red, blue and green, as well as various combinations of the indicated colors. By the way, almost all other representatives of the animal world can only distinguish the colors they need to survive in the wild. For example, carnivores can only distinguish red from others, herbivores can distinguish green or brown.
Color vision impairment, or color blindness, is color blindness, in other words, the inability to separate three primary colors, two or one of them.
Color vision impairment is a feature of the visual function that a person is endowed with from birth. The phenomenon is caused by the X chromosome and, as a rule, is transmitted at the genetic level from mother to male child. For this reason, color blindness often pursues the stronger sex. People with color vision impairments are unable to distinguish three colors – green, blue and red.
However, color vision disorders that a person acquires on the path of life can also be observed. The causes of such disorders can be diseases of the eye retina, damage to the nerves of vision or visual centers in the central nervous system. Color vision disorders of acquired origin can occur in one eye or in both, and are usually characterized by a disorder in the selection of all primary colors at once. With such a disease, a color blind person can see everything around him only in blue, red or green. When the underlying pathology is cured, color blindness is also cured, and a person’s vision returns to normal.
What is the peculiarity of the vision of people with color perception disorders
As many people know, the human eye is a kind of device for collecting and refracting light rays that emanate from various objects in a person’s environment. Refracted rays focus on the retina, which in turn is a complex of receptors responsible for receiving information. The retina of the human eye is composed of rods and cones. These rods and cones transport the information received by the retina to the nerves of vision, which transmit the data to the brain.
The cones, which can be of three varieties, are responsible for the perception of colors. The types of cones are determined by the presence of pigment in them, which is responsible for the perception of only blue, only green, or only red. People with all three types of cones have normal color perception.
Types of color vision disorders
The peculiarities of people’s vision are determined by the type of color vision disorder.
The first type of color vision impairment – trichromasia – assumes that a person can distinguish all primary colors, but sees them very dimly.
The second type of color vision impairment is called dichromasia, when a color blind person sees any two colors, except for the third, any of the three. This type of color blindness is more severe than the first type. In the absence of the ability to distinguish red, protanopia occurs, in the inability to distinguish green – deuteranopia, if it is impossible to distinguish blue – tritanopia.
The last type of color vision impairment is called monochromacy, in which there is a complete lack of color perception, complete color blindness. In other words, a person suffering from monochromaticity is able to see the world around him only in black and white.
Trichromasia is more common than other color perception disorders. The presence of this deviation in a person is detected after specific studies and tests.