Arc flash when turning the eyeball may be caused by visual fatigue, retinal ischemia, vitreous clouding and so on. 1. Visual fatigue: patients may have visual fatigue due to high mental stress, frequent late nights and excessive eye use, which may lead to the phenomenon of curved flashes of light when rotating the eyeballs. 2. Retinal ischemia: retinal tissue is where the visual neurons are located, once ischemia occurs, the optic nerve will be involved and damage will occur. Therefore, retinal ischemia may also lead to the phenomenon of arcuate flash when turning the eyeball. 3. Vitreous clouding: With age, the vitreous humor in the eye will liquefy and become cloudy, resulting in flashes of light when turning the eye. Generally, no special treatment is needed. When the patient appears to turn the eyeball with arc-shaped flash, it is recommended to go to the regular eye hospital for examination, to determine the cause of the disease, and then give targeted treatment.