Sudden flickering of light and shadow in the patient’s eyes, mostly referred to as a flashing sensation, may be caused by posterior vitreous detachment, retinal detachment, and so on. Aging patients and patients with high myopia are prone to vitreous degeneration, resulting in posterior vitreous detachment and liquefaction, which pulls the retina at the posterior detachment to stimulate retinal cells, and thus the patient may experience flashes of light in front of the eyes. If the force of pulling the retina from the posterior vitreous detachment is large, it can lead to retinal tears or even retinal detachment, and patients may experience frequent flashes of light in front of their eyes, accompanied by vision loss and black shadows in front of their eyes. It is recommended that patients with frequent flashes of light in front of their eyes and other discomforts should consult a doctor for evaluation of their condition and follow the doctor’s instructions for treatment.