China is a country with a large prevalence of myopia, and we have a high prevalence of high myopia, with a prevalence of 6.9% in a small population. Myopia over 600 degrees is high myopia. Many people feel that myopia is not a big problem and that it is no different from normal people as long as they wear glasses, but this view is not entirely correct. In fact, this view is not entirely correct. Generally, after adolescents mature, the number of myopia will basically stop increasing. However, there are a few high myopia occurs earlier, myopia will continue to deepen with age, and even up to 2000 degrees or more. In addition, a variety of pathological changes often occur in the fundus of the eye, which can be very harmful to patients and can even cause blindness. High myopia is not only the inability to see, but most importantly, the shape of the eye may change, i.e., the anterior and posterior diameters lengthen. As the shape of the eye changes, the retina and choroid at the back of the eye will be stretched, leading to retinal choroidal degeneration, so high myopia may develop into “pathological myopia”. If a fissure develops, it can lead to retinal detachment, which can result in blindness. Retinal detachment and macular atrophy are the two main causes of high myopia blindness. In general, for every 300 degrees of myopia, the anterior and posterior diameters of the eye increase by about 1 mm. Therefore, the higher the degree of myopia, the greater the risk of retinal detachment. According to statistics, about 70% of retinal detachment patients are nearsighted, and 30%-40% of them are highly myopic. Pathological myopia often presents with symptoms such as floating black shadows in front of the eyes, sudden loss of vision or discoloration of vision. High myopia is caused by the liquefaction of the vitreous humor, and as the eye rotates, black shadows often appear in front of the eyes, like flies flying around. As the eye becomes larger, it causes constant pulling on the retina at the bottom of the eye, especially when the small blood vessels in the macula rupture due to pulling and other factors, or when neovascularization is formed, it will cause macular hemorrhage and cause great damage to the central vision. When there is little bleeding, there is discoloration of vision; when there is much bleeding, the patient feels that there is a fixed black shadow in front of his eyes to block his vision. In addition, the retinal tissues of highly myopic patients become very fragile due to degeneration and atrophy, which can cause retinal rupture and blindness due to retinal detachment when subjected to sudden impact from external forces. Therefore, when people with high myopia suddenly experience vision loss, dark shadows floating in front of their eyes, flashing sensations, or when they feel a fixed dark shadow covering their eyes, they should go to the hospital as soon as possible to see a specialist ophthalmologist for an examination. The purpose of fundus examination is to observe changes in the retina, and if retinal degeneration areas or fissures are found, laser or surgical repair should be done in time to prevent further development to retinal detachment. If surgery is performed in the early stage of retinal detachment, the success rate is over 90%, therefore, early detection and early treatment are of great significance. Take appropriate amount of vitamins A, C and E, eat less spicy food, avoid smoking and alcohol, and use vasodilators carefully to prevent recurrent bleeding in the macula of the fundus. Avoid trauma to the eye and strenuous explosive movements. Choose refractive surgery carefully, LASIK is appropriate below -15.00D; intraocular lens implantation can be considered above -15.00D. Choose your career carefully, you should avoid heavy physical labor and jobs that use too much eye, and the unit hiring should be taken care of.