Bright flashes of light while sleeping with the eyes closed are usually what is commonly referred to as a flashing sensation and can be seen in patients with vitreous liquefaction. In these patients, the retina is stimulated to discharge due to the collapse of the vitreous humor caused by vitreous liquefaction, and they may feel bright flashes of light when they sleep with their eyes closed.
The vitreous humor in the eye is a jelly-like substance that gradually liquefies with age. The periphery of the vitreous body is adherent to the retina, and vitreous liquefaction begins in the center, with the periphery collapsing toward the center. When the vitreous body liquefies and collapses, a tugging irritation occurs in the retina, resulting in a sensation as if light flashes when you sleep with your eyes closed.
There is no need to worry about the flashing sensation in general, however, if there is a sudden loss of vision or blockage of vision in the eyes, please go to the hospital immediately for an examination to observe whether a retina-related disease has occurred, and treat it promptly under the guidance of a doctor.