Green weakness can be divided into two types: congenital and acquired. Congenital green weakness is further divided into two types: ocular pathology and no ocular pathology. Acquired green weakness is usually caused by eye diseases. Therefore, in clinical practice, when examining green weakness, it is necessary to differentiate congenital from acquired for diagnosis. I. Congenital green weakness: 1. Green weakness is determined by two pairs of genes on the X chromosome, namely the red weakness gene and the green weakness gene. Since these two pairs of genes are closely interlocked on the X chromosome, a gene symbol is commonly used to represent them. The red-green weakness is inherited in an X-linked recessive manner. Males have only one X chromosome and therefore only need one color weakness gene to show weakness. Females have two X chromosomes and therefore need a pair of disease-causing alleles to exhibit the abnormality. 2. The corresponding lesion organ is the eye, in detail the retina, and in further detail the optic cone cells. The morphology of the retinal cone cells is similar to that of the optic rod cells. The cone cell cytosol is located in the lateral part of the outer nuclear layer, with a larger nucleus 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. The membrane disc is embedded with the optic pigment that can sense strong light and color perception, which is constantly synthesized and replenished by the inner segment. Second, acquired green weakness: 1, the macular degeneration of the retina accompanied by old age, will cause changes in color vision. 2, cataracts block certain light and affect color vision, especially dark gray, dark blue, dark green, often not easy to distinguish clearly. 3. Trauma or lesions to the retina or optic nerve can also cause color blindness of varying degrees; certain medications may affect color vision, such as mullein, which is used to treat heart disease.