There are several types of color vision disorders, the most common of which is red-green color blindness. Also known as second color blindness, patients with green color blindness cannot distinguish light green from dark red, purple from cyan blue, or fuchsia from gray, and see green as gray or dark black. It is not easily detected because the patient has not had normal color discrimination since childhood. It is generally believed that red-green colorblindness is determined by two pairs of genes on the X chromosome, the red-blind gene and the green-blind gene. Because these two pairs of genes are closely linked on the X chromosome, a gene symbol is commonly used to represent them. The mode of inheritance of red-green color blindness is X-linked recessive. Males have only one X chromosome and therefore only need one color blindness gene to exhibit color blindness. Females have two X chromosomes and therefore need a pair of disease-causing alleles to exhibit the abnormality. A normal female who is married to a colorblind male can pass the father’s colorblind gene with the X chromosome to their daughter, not to the son. The daughter then passes the color blind gene from her father to her son, a phenomenon known as cross-genetic inheritance. As a result, there are far more males than females. The corresponding diseased organ is the eye, in detail the retina, and in further detail the cone cells. Retinal cone cells: the cell morphology is similar to that of the optic rod cells. The cone cells are located in the lateral part of the outer nuclear layer, with larger nuclei and lighter staining. The cones are also divided into inner and outer segments. The membrane disc of the outer segment is mostly not separated from the cell membrane, and the top membrane disc is not detached, and the membrane disc is embedded with optic pigments that can sense strong light and color perception, which are constantly synthesized and replenished by the inner segment. In humans and most mammals, there are three types of optic cone cells with red-sensitive pigment, blue; blue-sensitive pigment and green-sensitive pigment, which are also composed of 11-cis-retinal and retinoid, but the structure of retinoid is different from that of optic rod cells. If there is a lack of red (or green) light-sensitive cone cells, they cannot distinguish red (or green) colors and are red (or green) color blind. The end of the cone cell is expanded in the shape of a foot and can form synapses with one or more dendrites of bipolar cells and horizontal cells. There are approximately 12,000,000 optic rod cells and 7,000,000 optic cone cells in a human eye. In the central macular recess, there are only cone cells and no optic rods, and only at the edge of the central recess do the rod cells begin to appear.