Definition of Flashes in Eye

Flashes – visual phantoms that appear as spots of light. An ophthalmologist should evaluate occurrences of flashes, as they can be symptoms of retinal detachment or other conditions affecting the retina.

Flashes represent stimulation of the rods and cones, the cells of vision carpeting the retina, that occurs when the gelatinous fluid holding the retina in place (vitreous humor) moves across them.

Because the nerve signals these cells send to the brain encode patterns of light, the brain interprets messages from them as light. A blow to the head that causes a person to “see stars” has similar effect when it is forceful enough to jostle the vitreous humor against the retina.

Flashes may appear as multiple spots of light, “light showers,” or lightning-like streaks.


The ophthalmologist typically performs a full ophthalmic examination to assess the integrity of the retina. Prompt treatment is necessary to intervene with a retinal tear or retinal detachment, to preserve vision. Isolated flashes of light generally are harmless and may occur for various reasons.

Lines or waves of light that last 20 to 60 minutes are common with migraine headaches and have no significance for vision or the health of the eye.


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