What is the definition of high myopia? Myopia >600 degrees or more is called high myopia and is a common disease in the Asian population, with a prevalence of about 4%. Some of these patients’ myopia deepens with age, even after the age of 60, up to 4000 degrees or more. These patients have a progressive lengthening of the eye axis and are also known as pathological myopia or malignant myopia because of pathological changes in the fundus of the eye. High myopia can cause a series of complications such as cataract, glaucoma, fundus lesions, etc. Among them, high myopia fundus lesions affect vision the most, including macular degeneration, chorioretinal atrophy, retinal detachment, etc. Early detection and prevention of the development of high myopia fundus lesions is a key issue in their treatment. A systematic understanding of high myopia in terms of the types of high myopia fundus lesions, the process of disease development, auxiliary examination methods, and treatment can better cope with and manage this disease. What are the causes of high myopia? Genetic and environmental factors are involved in the development of myopia. High myopia has a clear genetic predisposition, and the incidence of myopia in the offspring of two parents with high myopia is significantly higher than that of normal people. Environmental factors that trigger myopia include close work, over-adjustment, reading habits, excessive or weak lighting, form deprivation, image quality changes, and micronutrient deficiencies.