Flashing lights in the eyes (photopsia): What causes them?
Seeing flashing lights in the eyes (photopsia) is a symptom of various conditions, some of which may be hard to diagnose. Photopsia may appear suddenly and intermittently as flashes, zigzags, dots or pinpoints of white light in your eyes. You may also see flashes of light in other shapes or colors.
Some of the conditions that can cause you to see flashing lights are serious (a detached retina), while others generally are not (a migraine with aura). If you’re experiencing the lights patients often refer to as “eye flashes” it’s important to see an eye doctor right away.
What causes eye flashes? (Photopsia causes)
Photopsia can be a symptom of various conditions, some of which require urgent medical attention. Conditions that may cause flashes of light in the eyes include:
A detached retina — Flashing lights in the eyes may be a symptom of retinal detachment, which is a medical emergency because it can lead to vision loss if not treated promptly with surgery. A detached retina happens when part of the retina, a thin membrane that contains light receptors, separates from the back of the eyeball.
Symptoms of a detached retina may include a dark “curtain” blocking part of your vision, blurry vision in one eye, eye floaters and flashes of light. Some patients describe eye flashes from a detached retina as similar to a camera flash or lightning.
Macular degeneration — There are two types of age-related macular degeneration: dry and wet. Dry macular degeneration normally does not cause photopsia, but wet macular degeneration is a common cause of flashing lights in the eyes.
Patients may see white circles of light, flickers, sparklers, pinwheels, squiggles or pulses of light. You may also see blue, gold, silver or multicolored lights.
A head injury — A hard blow to the head can cause photopsias that look like stars, which is why we use the expression “seeing stars.” This happens when a sudden impact shakes the vitreous gel inside the eyeball. If you see stars after hitting your head, this may be a sign of a concussion, which requires urgent medical treatment.
Medications — A heart medication, digitalis, may cause photopsia in some patients. Patients with digitalis toxicity may see “innumerable points” of light in the peripheral vision, according to the Annals of Internal Medicine.
Malaria medications such as chloroquine (Aralen) and hydroxychloroquine (Plaquenil) also may cause photopsia, according to the Review of Ophthalmology. These drugs were studied for treatment of COVID-19, but the U.S. Food & Drug Administration states that they are “unlikely to be effective” for coronavirus and may have serious side effects.
Migraine auras — A migraine with aura is a migraine with sensory disturbances that may include seeing sparks, bright dots or “zig zags” of light, according to the American Migraine Foundation. These flashes of light usually occur in both eyes.
This type of migraine, also called a “visual migraine,” is different from an ocular migraine, which is more serious and may cause temporary vision loss in one eye. An ocular migraine is caused by reduced blood flow or spasms in blood vessels behind the retina.
Visual changes from diabetes — Diabetes can cause vision changes that may include diabetic retinopathy. High blood sugar levels can damage the blood vessels in the retina. Eye floaters and flashes of light are common symptoms of diabetic retinopathy. Regular eye doctor visits are key to preventing vision loss from diabetes.
Photopsia may be caused by something other than a medical condition or injury. Do you ever recall seeing flashes of light after rubbing your eyes? You may also see bars of light, bright spots or swirling colored lights. The flashes of light you see after rubbing your eye are phosphenes — lights or images generated by electrical activity in the eye cells.
SEE RELATED: Eye floaters and flashes: Likely causes
Flashes of light in peripheral vision
Some conditions may cause flashes of light in the peripheral vision. The normal process of posterior vitreous detachment (PVD) that happens with age may cause flashing light in the corner of the eye. Retinal tears and retinal detachment also may cause eye flashes in the peripheral vision.
PVD and flashes of light in the corner of the eye
The retina is attached to the vitreous, the gel-like substance that gives the eyeball its round shape. As we age, the retina naturally separates from this gel. This usually harmless process may cause floaters and flashes of light. You may see a curved streak of light or a quick flash of light in the corner of your eye.
A retinal tear and flashes of light
Retinal tears can happen from trauma but usually happen spontaneously. In some patients, the vitreous sticks to the retina during the normal process of PVD. This can pull the tissue of the retina and cause a retinal tear.
A retinal tear can lead to a retinal detachment, which requires surgery to prevent vision loss (or further vision loss). Risk factors for a retinal tear include age and having myopia (nearsightedness). Retinal tears and retinal detachment also can lead to seeing flashes of light in the peripheral vision.
Your eye doctor will need to conduct a comprehensive eye exam to determine if the flashes of light you’re seeing in the corner of your eye are being caused by PVD, a retinal tear or retinal detachment.
Eye floaters and flashes of light
You may experience flashes of light and eye floaters at the same time. Eye floaters are specks or blobs that appear and seem to move around in your field of vision. Floaters are caused by shadows cast by clumps of collagen that float in the vitreous (gel-like substance) in your eyeball. They are a common symptom of certain eye problems and may occur along with flashes of light.
Common causes of eye floaters and flashes of light are: PVD, a retinal tear and retinal detachment.
SEE RELATED: Eye floaters and flashes: What's the difference?
Seeing flashes of light? See an eye doctor
It’s important to get regular eye exams to keep your eyes healthy. It’s also helpful to have an established relationship with an eye doctor in case you ever experience eye symptoms such as flashing lights.
To find the cause of flashing lights in the eyes, an eye doctor may conduct a comprehensive eye exam, including ophthalmoscopy (also called fundoscopy or a fundoscopic exam). The doctor will examine the back of the eyes with a special light to check for retinal tears, detachment and other issues. Your eyes may need to be dilated with eye drops for this exam.
Remember, seeing flashing lights in your eyes could indicate a detached retina or other serious problem in the eye and you should visit your eye doctor without delay.
Page published in February 2021
Page updated in November 2021