What Flashes May Mean About Your Eye Health
Are you wondering why you see little flashes of light? The light show could actually be coming from inside your eyes. Flashes can be a sign of a serious vision problem, but are usually a harmless sign of aging.
What Are Flashes?
Flashes only appear for seconds at a time and may look like lightning bolts, streaks, stars, or tiny pinpoints of light. Although flashes are most noticeable when it's dark, they can appear at any time. Flashes often appear along with floaters. Floaters may look pieces of string, cobwebs, lines, or other shapes.
Causes of Flashes
Flashes can be caused by:
- Rubbing Your Eyes. Do you see stars after you rub your eyes? Rubbing your eyes, coughing, and sneezing all stimulate the retina, causing it to produce phosphenes, tiny bursts of light. Phosphenes don't harm your vision or last more than a few seconds.
- Normal Age-related Eye Changes. A clear, gel-like substance called the vitreous humor gives your eyeball its shape. As we age, the vitreous humor starts to shrink and pull away from our retinas, the light-sensing tissue at the back of the eye. Called posterior vitreous detachment, this condition causes an increase in the number of flashes or floaters you see. More than 80% of people who experience posterior vitreous detachment don't develop any complications, according to the AARP. For some people, posterior vitreous detachment can lead to retinal detachment.
- Retinal Detachment. In some cases, an injury or posterior vitreous detachment can cause the retina to tear or detach from the back of the eye. If this happens, you may see a significant increase in floaters and flashes, develop a dark spot in your vision, or even experience complete loss of vision. If this happens, go to the emergency room immediately. You'll need prompt treatment to reattach and repair your retina to restore your vision.
- Migraines. You might also see flashing lights if you're experiencing a migraine aura. Auras appear about a half-hour to an hour before a migraine starts and can include flashing lights, zigzag lines, colorful lines or shapes, blind spots, blurry vision, temporary loss of vision, slurred speech, and tingling, numbness, or weakness.
- Diabetic Retinopathy. Poorly controlled diabetes can be a factor in diabetic retinopathy, an eye condition that affects the blood vessels in the retina. More than 33% of people over 40 with diabetes have diabetic retinopathy, according to the Centers for Disease Control and Prevention. Blood vessels in the retina may leak if your blood sugar is too high. New abnormal vessels may also form and leak blood or fluid. Blood and fluid interferes with vision and may cause scar tissue to form. If the scar tissue pulls on the retina, you may see flashes and floaters.
- Macular Degeneration. Scar tissue caused by the wet macular degeneration may also pull on the retina and trigger flashes and floaters. Macular degeneration affects the macula, the center part of the retina responsible for central and color vision.
- Other Causes. You may also see flashes of light if you have a concussion or look at bright lights. Several diseases can cause flashes, including HIV/AIDs, retinitis pigmentosa, cytomegalovirus retinitis, Stickler syndrome, and choroideremia.
Although occasional flashes usually don't mean that there's anything wrong with your vision, it's important to call your eye doctor if you notice a significant increase in the flashing lights or see flashes frequently. If an increase in flashers is accompanied by loss of vision, visit the emergency room immediately.
Worried about flashes, floaters, or other vision issues? Get in touch with our office to schedule a visit with the optometrist.
AARP: What to Know About Eye Floaters and Flashes, 3/11/2019
Centers for Disease Control and Prevention: Diabetic Retinopathy
American Academy of Ophthalmology: Flashes of Light, 1/19/2022
The Ohio State University: Why Do You See Colors When You Close or Rub Your Eyes?, 7/3/2019