Men! Do you find it hard to choose clothes to match in color, the fruit select ripe, to distinguish the colored image on the computer monitor, the green and red traffic signals? Or someone helps you to do this? This suggests that you have a disorder of color vision, or as it is called – a violation of color vision.
This problem occurs most often in every 12-year-old male of Caucasian race and of every 200 women. Most sufferers of violation of color vision see not only black and white but also other colors, but some of them they perceive differently than people with normal vision. As a rule, violation of color vision is inherited. Defective gene disrupts the light sensitive cells in the retina or internal membrane of the eye. But sometimes color vision can be compromised by disease, then you need to consult an eye specialist.
In the retina of the human eye usually has three types of light-sensitive cells or cones that are sensitive to light waves of a certain length and match the colors: blue, green and red. Each type of cone absorbs the light wave and sends pulses to the brain and the person correctly perceives color. But in violation of color vision sensitivity of the cones is reduced to a single color or multiple, or the perception of the wavelength is changed and affects the vision. Most people suffering from this disorder, do not distinguish colors: green, yellow, orange, red and brown. So they don’t notice green mold on black bread or yellow cheese and not tell a blond from a red-haired man. When the sensitivity of cones, which are responsible for perception of red, sharply reduced, the red rose seems to them black. Cases of color blindness for blue color is very rare.
As already mentioned, a disorder of light sensitivity is inherited and is usually congenital. But many know about it only when I grow up. The fact that the children disturbed perception of colors often kompensiruet the ability to unconsciously distinguish between them in brightness or contrast. Your perception of children associated with common color names. In addition, they learn to distinguish objects by shape or texture, not color. And as adults they learn that suffer a violation of color vision since childhood.
The school often uses colored benefits, particularly in the early grades. And if the child is not able to properly distinguish colors, teachers and parents mistakenly conclude that the child is not capable of learning. And in fact, he may have a violation of color perception. Sometimes, the teacher even punishes the child for something that he paints green people, brown leaves on the trees and pink clouds, but the child finds such colors absolutely normal, he just disturbed color vision. In some countries, for this reason, even small children are examined to identify color blindness.
Although the disorder of color vision considered incurable, other visual functions do not deteriorate with age. But, nevertheless, this disease some causes spiritual experiences.
Why the breach of color vision happens mostly in men? For inherited color vision meets the X chromosome. Women have X chromosomes two and males have one X chromosome, the other Y. When a woman has one X chromosome the gene is damaged, it compensates for a healthy gene on the other X chromosome and she has normal vision is maintained. While males have no backup X chromosome, so the defect is not kompensiruet.
How is vision screening for color perception:
Vision screening for color perception is performed on special tables with the image of multi-colored circles. For this purpose often use the 38 Ishihara tables. If a person has normal vision, considering the tests to the left in daylight, he would see numbers 42 and 74. If a person has a disorder of perception of red and green (this often happens), it does not distinguish a figure at the top, and sees the figure 21 below. Here are the tests only as an example, as the survey must be performed by a qualified doctor. In identifying violations of the doctor will prescribe additional tests to determine the cause – it is hereditary or acquired.