What is a weak color?

Concept of weak color: the ability of human eyes to distinguish colors is impaired.

Weak color is also called "abnormal trichromatic vision". Color vision defect. Mild color blindness, able to recognize colors, but low sensitivity.

1875, a serious train collision occurred in Laagland, Sweden-because the driver was color blind and misread the signal. Since then, color discrimination has become an essential item for physical examination.

Generally speaking, color blindness means that you can't distinguish some or all colors, and color weakness means that your ability to distinguish colors is reduced. Color blindness is more common in red and green color blindness. The red blind can't tell the red light, and the green blind can't feel the green, which will undoubtedly have an impact on life and work. Weak color is mainly due to low color discrimination function, lighter than color blindness, and weak bonus color and green color. People with weak colors can see the colors seen by normal people, but their ability to recognize colors is slow or poor. When the light is dim, some of them are almost color blind or show color fatigue. Congenital factors are common in color blindness and color weakness.

Color blindness and color weakness are collectively called color vision disorders, which are divided into two categories: congenital and acquired. Red-green color blindness is the most common congenital color vision disorder, which is a genetic disease and is recessive through sexual linkage. In other words, a color-blind person passed the genetic gene (X chromosome) from his daughter to his grandson (male). That is to say, his grandfather showed red-green color blindness and passed it on to his daughter, but his daughter did not show color blindness but passed on the genetic factors to his son, that is, his grandson showed color blindness. Only daughters born to mothers with color vision disorder genes and color-blind fathers show color blindness. Therefore, the incidence of color blindness in men is higher than that in women, which is five times that of women.

Congenital color blindness or color weakness is a hereditary disease, which is related to gender. Clinical investigation shows that male color blindness accounts for 4.9%, while female color blindness accounts for only 0. 18%, and the number of male patients greatly exceeds that of female patients. This is because the genetic gene of color blindness exists on the X chromosome of sex chromosome and adopts the recessive inheritance mode of sex linkage. Usually, men are color blind, and women are color blind gene carriers with normal appearance, so there are more color blind men than women.

Congenital color vision disorder remains unchanged for life, and there is no specific treatment at present. Red or green soft contact lenses can be worn to correct it. Some people try acupuncture or traditional Chinese medicine, which is said to have certain effect, but it is still in the clinical research stage. Because color blindness and color weakness are hereditary diseases and can be passed on to future generations, it is an effective preventive measure to avoid consanguineous marriage and investigate the genetic disease history of the other family before marriage and take measures to reduce the birth rate of color blindness offspring.

A few color vision abnormalities are also found in acquired people, such as some fundus diseases and glaucoma. The degree of color vision disturbance caused by these eye diseases is relatively light and disappears with the recovery of primary eye diseases, so most of them have not attracted the attention of patients.

Pseudohomography

It is usually called a color-blind book. It uses dots with the same tone depth but different colors to form numbers or figures, which can be seen clearly at a distance of 0.5m in natural light. Color blindness should be corrected during inspection, and each picture should not exceed 5 seconds. People with color vision impairment have difficulty in recognizing, misreading or being unable to read, and can confirm what kind of color vision abnormality they belong to according to the regulations of color blindness table.

Note that the color vision chart in China is not standard at present. When using the red-green isomorphic examination chart, we should correctly understand some people who are so-called red-green color blindness or weak color, but actually have normal color vision. People with normal color vision have three kinds of cognition: one is the cognition of color first, the other is the cognition of light and shade first, and the other is the cognition of color and mixed light and shade. It is difficult for some people to distinguish the patterns that red and green are mixed together at the same time, because in the eyes of this group of people, red has high activity and green has high activity. When red and green are mixed together, they will turn to the perspective of light and shade. It is worth noting that many people with normal color vision can't see the patterns or numbers in the chart clearly and are wrongly classified as color blindness or color weakness. This is a cognitive habit problem of the brain, not a problem of color perception and discrimination. For example, when the red light is on, it is connected to the red light, when the green light is on, it is connected to the green light, and the traffic lights are on at the same time. What kind of lamp is it? If you can't answer, it's called red-green color blindness, or red-green color weakness. This is the real situation of color inspection now. Either red is normal and green is weak, or green is normal and red is weak, because when red and green are in the same picture, it is wrong to see the patterns or numbers at first sight. It should be difficult for normal people to read the red and green dots in the same picture, because these two colors are very exciting, which is equivalent to mixing salt and sugar and asking if you are sweet or salty, but all the people who can't taste it at once are normal people. Therefore, the person who concocts the so-called red-green isomorphic color inspection should be red-green-monochrome. There is no doubt that most people in China are monochromatic and weak, which is a comparison of a large number of domestic and foreign color cases.