Flashes and Flickering Light in Eye: When to See a Doctor

Diagnosing flashes (and floaters)

After you call and make an appointment, here’s what you can expect, says Colin McCannel, M.D., a specialist in retina and vitreous diseases at UCLA Health in Los Angeles:

• Vision exam
• Eye pressure check
• Dilation to examine the retina
• A scleral indentation exam, possibly. (This is more likely to occur if you see a retina specialist, says McCannel.) It involves gently pushing on the sclera (white part of the eye) in order to view the peripheral retina, the part that’s not normally visible. “We want to see 100% of the retina because tears can be hiding anywhere,” he says.

Following the exam, your doctor may diagnose you with:

• PVD: Posterior vitreous detachment. At this point, you don’t need a specific treatment. Most likely, the eye gel will gradually detach from the retina over the next few months with no problems. Your eye provider will want to follow-up with you within a three-month period to watch for complications, like tears, according to the American Society of Retina Specialists. You should also watch for escalating symptoms, like a sudden increase in flashes and floaters, and call your eye care professional if that happens.
• Retinal tear: When that gel in your eye moves around and tugs on your retina, it can cause a tear. This allows fluid from the eye to move into the hole and under the retina.
• Retinal detachment: A tear can progress to a detachment where the retina is pulled away from the back of your eye, an event that’s considered a medical emergency, per the National Eye Institute (NEI). You may also see a dark shadow or “curtain” encroaching on the sides and middle part of your vision.

Remember, just because you have a flash does not mean that you have a retinal tear or detachment, and in fact, most times these aren’t found at all, says McCannel. “We like to do these exams every single time because it’s such a big deal to have a retinal detachment,” he says.

Treating a retinal tear

Retinal tears allow fluid to seep under the retina, pulling it off the eye wall and causing vision loss, which is why quick treatment is needed, says Thomas. When a tear advances to a detachment, it can lead to lasting vision loss or changes in vision, such as blurriness or distortion. “Treating a tear early allows us to avoid surgery and permanent vision loss,” she says.

The mainstay of treatment for a tear is a laser treatment called laser retinopexy. “We apply laser scars around the area of the tear, creating barricades,” says Thomas, likening these to “welding spots.” The idea is that by sealing up these holes, you can stop fluid from going underneath that would worsen the tear and possibly lead to a detachment.

This in-clinic noninvasive procedure takes about 10 minutes –a huge benefit to detecting a tear early, says Thomas. Although those seals will stay put, you’ll need to go back for a follow-up appointment to check for additional tears. If that’s the case, you’ll get another laser treatment. But once the vitreous (eye gel) finishes separating from the retina, your risk of another tear is low, she says.

Retinal detachment, however, requires surgery in an operating room. The procedure's goal is to reattach the retina to the back of the eye and uses laser treatment to repair any retinal tears. Nine out of 10 of these surgeries are considered successful, says the NEI, though complications such as additional detachments or the need for multiple surgeries can occur in the remaining cases, adds McCannel.

Can you prevent a retinal tear?

Unfortunately, it’s not something you can predict or necessarily avoid. “It’s a degenerative change in the inside of the eye,” says McCannel. Although there are so many things you can do to promote good eye health as you age — such as following a nutritious diet — there are no lifestyle changes that prevent or delay a vitreous separation.

Still, certain risk factors may increase your likelihood of developing a retinal tear or detachment, says Chiang:

• Being over age 50
• Being very nearsighted (myopia)
• Family history of a retinal tear or detachment
• Past eye trauma

Flashes in the eyes can be signs of other health issues

Flashing lights in your vision doesn’t always mean there’s an eye problem at all, but they still warrant prompt medical attention. Doctors might explore these possible non-eye-related causes:

Retinal migraine: A type of migraine attack that comes with twinkling lights, loss of vision, and even temporary blindness in one eye, with episodes lasting up to an hour, according to the American Migraine Foundation. Often, you won’t notice any headache, which can make these attacks feel surprising and a bit confusing. If you may have this type of migraine attack, see a neurologist.

Vertebrobasilar insufficiency (VBI): This condition features a slowdown in the circulation to the back of the brain, says Chiang. “This can produce flashing lights,” he says. You’re more at risk if you have coronary artery disease, diabetes, high cholesterol or blood pressure. VBI also increases your risk of a ministroke and stroke. Flashing in both eyes may be more indicative of a circulation problem (rather than a vision problem), says Chiang. See your cardiologist for an evaluation.

Stroke: Common warning signs of stroke include face drooping or twisting, arm weakness and speech difficulty. However, certain types of stroke can also come with visual symptoms–flashing light, difficulty moving eyes, missing fields of vision, blurred or double vision– which may often be missed or confused for another problem by both patients and healthcare providers, according to research. Prompt medical attention is crucial if you experience any of these symptoms. Be sure to describe them in detail to your healthcare provider. If you're having a stroke, treatment with medication to dissolve the blood clots blocking blood flow must be administered within 4.5 hours of symptoms onset.

Eye stroke: An eye stroke is a blockage of blood flow to the eye, a condition called retinal artery occlusion. Completely losing your vision, loss of peripheral vision, distorted vision, and blind spots are all indications of an eye stroke. If you suddenly lose your vision, go to the ER immediately, advises the American Academy of Ophthalmology, as this can cause permanent vision loss.

Diabetic retinopathy: If you have diabetes, you’re at risk for developing diabetic retinopathy, a condition where there is abnormal growth of blood vessels in the eye. Symptoms, which typically occur in advanced disease, include blurry or double vision, floaters, eye pain or pressure, rings, flashing lights, and blank spots in vision, per Johns Hopkins Medicine. If you have been diagnosed with diabetes, managing your blood sugar and getting regular eye exams will help slow the impact diabetes has on your eyes.

When should I seek emergency care?

Sudden loss of vision–whether painless or not–warrants a trip to the emergency room. If you have visual changes along with other signs of stroke, like face drooping or twisting, arm weakness, or speech difficulty, head immediately to the ER. For symptoms of a retinal detachment–new floaters, flashes, a shadow or curtain in the periphery or middle of your vision — head to the ER or call your eye care provider as soon as possible.