Myopia can be classified as mild, moderate, severe or super high depending on the degree of myopia. 300 degrees or less is called mild myopia; 325-600 degrees is called moderate myopia; 625-900 degrees is called high myopia; and 900 degrees or more is called super high myopia. Most mild to moderate myopia is simple myopia; a small percentage of high and ultra-high myopia may be pathological myopia, where the latter continues to deepen each year, the eye axis keeps growing, and common myopic fundus changes appear in the eye, such as hemorrhage of the macula, neovascular membrane, degeneration of the peripheral retina, leopard’s eye fundus, etc.