When the posterior vitreous detachment occurs in patients with high myopia, a flashing sensation may appear, usually the flashing sensation can disappear gradually, but the specific situation is related to the patient’s condition. Patients with high myopia are more likely to have posterior vitreous detachment. When the posterior vitreous detachment is incomplete, part of the vitreous body is not detached and adheres to the retina, and the retina is stimulated by the eyeball turning and pulling, it can cause the flash sensation. As the posterior vitreous detachment continues to progress, the vitreous body and retina are completely separated from each other, and the pulling stimulation of the retina disappears, so the flash sensation in front of the patient’s eyes can gradually disappear. Patients with posterior vitreous detachment, during the period when the flashing sensation still exists and the vitreous body has not been completely detached, should pay attention to avoiding strenuous exercise, otherwise it will increase the tugging stimulation to the retina, and may even cause the formation of retinal cracks and develop into retinal detachment. It is recommended that patients with high myopia who experience frequent flashes of light in front of their eyes should seek prompt medical attention to assess their condition and follow the doctor’s instructions for treatment.