Loss of color vision refers to an insensitivity to the ability to discriminate one or some colors. According to the doctrine of the three primary colors, loss of color discrimination of one color is called dichromatic vision, and loss of red color discrimination is called red-blindness. This person has a shortened red end of the spectrum and is less sensitive to the red color of the spectrum and sees it as a dark color. He drives through red lights, often because the red light is not bright enough for him. According to the doctrine of the three primary colors, loss of color discrimination of one color is called dichromatic vision, and loss of red color discrimination is called red blindness. This person has a shortened red end of the spectrum and is less sensitive to the red color of the spectrum and sees it as a dark color. Loss of green color discrimination is called green blindness. Yellow-blue color blindness is less common. Loss of color discrimination in both colors is called monochromatic vision, also known as panchromatic blindness, where only light and dark are distinguished. There are two types of panchromatic blindness: typical and atypical. Typical panchromatic blindness is also known as optic rod cell monochromatic vision, this person, although his color discrimination is not good, but the saturation and brightness of color is extremely sensitive, there is photophobia, low vision, young people can have persistent vertical nystagmus, visual field may have a small central dark spot, wear sunglasses can help tolerate normal sunlight, dark adaptation than normal people, normal people need 5 to 10min, while panchromatic blindness is in 1 to In normal people, it takes 5 to 10 min, but in panchromatic blindness, it takes 1 to 2 min to reach the level of adaptation. Atypical panchromatic blindness, also known as cone cell monochromia in the early literature, is characterized by “normal” cone cells, good visual acuity, no nystagmus or photophobia, normal dark adaptation and ERG, but complete loss of color vision. Color vision loss can be divided into two categories: congenital color vision abnormalities and acquired color vision abnormalities. 1, congenital color vision loss In 1986, Nathans et al. demonstrated from a molecular biology perspective that the human red-green color vision gene is located on the X chromosome, while the blue color vision gene is located on the seventh pair of autosomes. The abnormalities in color vision are due to unequal exchange and recombination of genes. Kollner was the first to suggest that retinal disease is dominated by yellow and blue disorders, while optic nerve disease is manifested by red and green disorders.