Degenerative myopia is also called pathologic myopia. Myopia can be divided into physiological myopia or simple myopia. The diopter generally does not exceed -6D diopter and progresses slowly. It can be stable around the age of 20, and the fundus changes are relatively mild. If the axial myopia is greater than -6D diopter, it is called high myopia (excessive myopia). The degree of myopia gradually deepens with age and can be as high as 20 to 35 diopters. The highest reported in the literature is 60 diopters. Degenerative myopia is different from general myopic refractive error. In addition to high myopia, it also has the following characteristics: ① Abnormal visual function: vision cannot be fully corrected, reduced light sensitivity, poor dark adaptation, visual field changes and electrophysiological abnormalities. ②Accompanied by a series of complications: progressive elongation of the anterior-posterior axis of the eyeball, enlargement of the posterior part of the eyeball, choroidal retinal degeneration, including retinal atrophy and staphyloma, pigment proliferation, focal choroidal atrophy, lacquer cracks, Fuchs spots, vitreous degeneration, posterior detachment and choroidal neovascularization, followed by retinal detachment, cataracts and glaucoma. The affected eyes are often accompanied by fundus degenerative changes and visual impairment.