Myopia greater than -6.00D (-600 degrees) is clinically called high myopia. Its clinical manifestations are: 1. Rapid myopia development: High myopia often develops rapidly at an early age, and a developmental peak occurs during adolescence (15-20 years old); unlike simple myopia, some high myopia does not stop even in adulthood, so it is also referred to as progressive myopia. 2. Eye protrusion: The anterior and posterior diameters of highly myopic eyes grow significantly, some form post-scleral staphyloma, the anterior chamber deepens, the ciliary muscle atrophies, and some people’s eyes protrude significantly. 3, black shadow in front of the eyes: High myopia can cause vitreous degeneration, liquefaction, posterior vitreous detachment, etc. There are turbid and floating objects in the vitreous, and patients can see flying mosquitoes, Mars dots and flashes. 4. Fundus changes: arcuate spots are visible next to the optic papilla, the retina is highly leopard-shaped, retinal atrophy spots (Fuchs spots) are visible, and macular degeneration. 5, vision loss: high myopia can cause cataract, macular hemorrhage, which can cause significant vision loss, and most seriously, retinal detachment, which can seriously lead to blindness and eye atrophy.