Seeing flashes of light is a concerning symptom that should prompt an immediate visit to your optometrist.
Eye flashes result when something other than light stimulates the retina, the light-sensing structure at the back of the eye. When stimulated without light, the retina sends a signal to the brain, which gets interpreted as a sudden flash of light similar to lightning, spots, or stars. These visual distortions are known as a photopsia. Sometimes these flashing lights can be due to a migraine that will eventually resolve on its own, however some photopsia can also occur when rubbing the eyes or due to a blow to the back of the head (seeing stars.)
Migraines can cause vision symptoms such as flashes of lights. These flashes can appear as white, jagged, flashing lines that appear in the middle of one’s field of vision and spread across the entire field of vision, rather than single spots or “floaters.” Flashes of light due to migraines often resolve themselves over approximately 20 minutes, disappearing first from the peripherals and finally from the center of one’s field of vision. These symptoms may or may not be accompanied by a headache, but if they are then its usually called a “visual or ocular migraine.” These are caused by a phenomenon in the brain, rather than stimulation of the retina.
Seeing flashes can be common between the ages of 50 and 75, due to the shrinking of the vitreous humor, which is the clear gel that fills the space in the eyeball. The shrinkage of this vitreous can simultaneously cause occasional tugs on the retina. These tugs can stimulate the retina, giving the illusion of flashes of light.
However, flashing lights can also be due to a number of less common, and more serious issues. Flashes of light could indicate a more serious retinal issue, including a detachment of the retina or a tear in the retina. Often, a detachment of the retina is accompanied by floaters or the sensation of a curtain coming down over the field of vision. Retinal detachment and tears are a higher risk in those with high nearsightedness (myopia), although they can occur at any prescription level. A retinal tear or detachment needs to be attended to promptly and repaired with surgery. If left untreated, a retinal tear or detachment can lead to permanent vision loss and blindness.
Warning symptoms that could accompany flashes of light to warn of a retinal detachment include:
If you are experiencing flashing lights with warning symptoms, floaters, or a curtain coming down in your field of vision, it is important that you contact your optometrist or visit an emergency room immediately.