Jagged flashes of light in the eyes are a symptom of a condition called flashing dark spots, which can also be called temporary incomplete blackout. The cause is spasm of the arteries in the talus cortex of the brain, and the flashes are a response to stimulation of the talus cortex. Each attack is before the onset of migraine, there is a sudden dark spot in the field of vision of both eyes, blurred vision, see a bright flash of gold, red and green, forming a horseshoe, jagged, gradually expanding to the surrounding area, which can be up to half of the field of vision, lasts for 15 to 30 minutes, and produces a severe headache after the dark spot disappears. Flashing dark spots are mostly caused by temporary ischemia of the cerebral cortical center, mostly occurring in young people, and are related to mental overstress and fatigue.