Probably, each of us has faced our way of life with people who perceive some colors differently or do not see them at all. And, perhaps, you and yourselves sometimes surprise the lives of loved ones and friends by the fact that they are not able to find any subject. In this case, vision testing is required for color blindness.
The medical definition of color blindness is expressed in violation of the perception of color. The inherited anomalies are transmitted as a recessive sign that is interlaced with the X-chromosome. All who are prone to color anomaly are trichromates, and they, as well as those with normal vision, need three colors, with which they can describe the visible color. However, in color-blindness, a person is worse than those with normal eyesight, distinguishing some colors. When checking the perception of colors, people with abnormal vision, comparing colors, use green and red, but in other proportions. In medicine, there are several different color perception anomalies, when visual examination is required for color blindness.
Examination of vision on color blindness
Testing for color blindness using an anomaloscope usually indicates that the prothanomalance of the color mixture is manifested in an increase in the perception of red color. Deuteronomy, characterized by very strong perception of green. Tritanomalia is very rare and is a violation of the blue-yellow channel.
Types of color blindness
Checking for anomalies of vision may reveal color blindness of the following types:
- Dichromates People suffering from this kind of visual anomaly can describe all the colors they see. However, they see only two pure colors. In protanopy and deuteranopes, the work of the red-green canal is broken, so they are confused with a red color with dark gray, black and brown. Some part of the spectrum when checking it seems to them achromatic. For rarely found tritanopia achromatic appears to be a part of the blue-violet spectrum. Dichromatopia, as well as other types of color blindness, is inherited as a recessive coupled X-chromosome with a sign.
- Complete color blindness, or monochromatosis. Very rare visual anomaly, which occurs in less than 0.01% of people. Monochrome people distinguish only two pure colors - black and white. This makes the world around them a black-and-white film, consisting of different gradations of gray. For such people is characterized by a strong violation of light adaptation, which makes the eyes monochromates easily blinded. Also, they poorly distinguish the shape of objects in bright daylight, which entails photophobia.
- Violation of the stick device is a normal perception of colors, but the test for anomalies of vision usually detects color blindness, as a rule, in people who have the so-called "night blindness". This means that they have a reduced ability to dark adaptation.
Because the disturbance of color perception is the congenital anomaly of the X-chromosome, the male half of the population most often suffers. In order to find out whether there are any signs of anomalies, a special test of vision is usually performed on color blindness in the form of a test. Such a test is carried out in polychromatic tables made in the form of colored circles and dots. The author of this famous technique is E. B. Rabkin