First, what is color blindness congenital color vision disorder is usually called color blindness, it can not distinguish the natural spectrum of various colors or a color; and poor color discrimination ability is called color weakness, color weakness, although you can see the colors seen by normal people, but the ability to identify color is slow or very poor, in the dark, some almost and color blindness or color fatigue, it is generally not easy to strictly distinguish the boundary with color blindness. It is generally not easy to distinguish from color blindness, but the degree of severity is different. Color blindness and color weakness to congenital factors are common. Color blindness is divided into total color blindness and partial color blindness (red blindness, green blindness, blue-yellow blindness, etc.). Color blindness includes total color blindness and partial color blindness (red weakness, green weakness, blue-yellow weakness, etc.). 1, total color blindness belongs to complete cone cell dysfunction, and night blindness (optic rod cell dysfunction) is the opposite, the patient especially likes darkness, photophobia, performance as day blindness. The seven-color world is gray in their eyes, just like watching a black and white TV, there is only a difference between light and dark, but no color difference. In addition, there are symptoms such as poor visual acuity, amblyopia, central dark spot, and oscillatory nystagmus. It is the most serious kind of color vision disorder, and patients are less common. 2, red blindness Also known as first color blindness. Patients are mainly unable to distinguish red, and cannot distinguish red from dark green, blue from fuchsia and purple. Often see green as yellow, purple as blue, and mix green and blue as white. There was a middle-aged man who bought a gray wool sweater and wore it, but he was ridiculed because he was a red colorblind person who mistook red for gray. In the early years, there were reports that a red colorblind patient became a train driver, because of the wrong signal and caused a train collision. 3, green blindness, also known as second color blindness, patients can not distinguish between light green and crimson, purple and green-blue, fuchsia and gray, green as gray or dark black. In an art training class, a child who drew very well always painted the sun green and the canopy of trees and grass brown, but it turned out that he was green color blind. The clinical term for red and green color blindness is red-green color blindness, which is more common in patients. We usually say color blindness is generally refers to red-green color blindness. 4, blue-yellow blindness also known as third color blindness. Patients with blue-yellow confusion, red and green can be identified, less common. 5, total color blindness also known as red-green-blue-yellow weakness. Its color vision impairment than the degree of total color blindness is lower, vision without any abnormalities, and no other complications of total color blindness. When the object is dark and sharp, it can be distinguished; if the color is light and unsaturated, it is difficult to distinguish. Patients are also rare. 6, partial color weakness There are red weakness (first color weakness), green weakness (second color weakness) and blue-yellow weakness (third color weakness), etc., of which red-green weakness is more common, the patient has poor perception of red and green, and when the illumination is poor, its color discrimination ability is close to red-green blindness; but when the material color is deep, sharp and good illumination, its color discrimination ability is close to normal. Prevention and treatment Prevention: Because color blindness and color weakness are hereditary diseases that can be passed on to offspring, it is an effective means of prevention to avoid marrying close relatives and to investigate each other’s family history of hereditary diseases before marriage, and to take measures to reduce the birth rate of color blind offspring. Treatment: The principle of wearing color blindness correction glasses is based on the complementary color antagonism, and the special coating on the lens, which produces the effect of cutting off the wavelength, transmitting to long wavelengths and reflecting to short wavelengths. By wearing color-blind glasses, the original color-blind chart that was illegible can be correctly identified. The effect of correcting color vision is achieved.