The sense of light when the eyes are closed may be caused by physiologic conditions or pathologic factors such as proliferative vitreoretinopathy. 1. Physiological conditions: the posterior vitreous membrane was originally tightly adhered to the retina, with age and other physiological reasons, can lead to vitreous liquefaction contraction, resulting in posterior vitreous detachment, which can pull on the retina, so the patient’s eyes can be closed with flashes of light and other uncomfortable symptoms. 2. Pathological conditions: when patients with proliferative vitreoretinopathy, a large number of organized material can appear in the vitreous body, and connected to the retina, with the eye activity can lead to organized material on the retina to produce pull, patients can have flash before the eyes. In addition, patients with retinal detachment may also experience flashes of light, which may be accompanied by symptoms such as blocked vision. It is recommended that patients who experience flashes of light in their eyes seek medical attention to evaluate their condition and treat them as directed by a physician.