Myopia of 600 degrees or more, especially those over 1,000 degrees or more, can easily cause retinal detachment. High myopia, also known as pathological myopia, is a condition in which the eye axis is longer than normal, the retina is very thin, and there are lattice-like changes or retinal fissures in the periphery. If left untreated, liquefied vitreous humor can enter the retina through the fissures and cause retinal detachment. Patients with high myopia need to have their fundus examined regularly at 6-12 months, especially when there is a dark shadow or flash in front of the eyes. Patients with high myopia, especially those with more than 1000 degrees, should avoid lifting heavy objects and avoid trauma to avoid retinal detachment.