Are Flashes and Floaters in Your Eyes Dangerous? by Dhanu Meleth, M.D.

July 10, 2020

Dr. Dhanu Meleth is an ophthalmologist with the Marietta Eye Clinic who specializes in retina and uveitis.

Flashes and floaters can result in obstruction to one’s view, and they can be frightening if you’re unsure of what they are or why they are present. Floaters can appear as spots, specks, or strings in your vision. Flashes look like flashing lights, sparkles, or lightning. They are usually benign but may be cause for concern in certain circumstances.

What Causes Flashes

Flashes are commonly caused by migraines, spasms of the blood vessels in the brain, or physical force on the retina. This can be caused by rubbing too hard on the eye, being hit in the eye, or through normal aging processes that cause the vitreous — the jelly-like substance in the eye — to pull on the retina. Ocular surgeries can also cause the vitreous to shift and pull on the retina.

What Causes Floaters

Floaters are characterized by the way they drift and then disappear when looked upon. The most common cause of floaters is age-related changes in the vitreous. While young, your vitreous maintains a firm, gelatinous structure, but as you age, it begins to liquify, break apart, and form clumps that cast shadows on the eye.

Though less common, floaters may also be caused by the following:

  • Bleeding in the eye due to diabetes, trauma, or high blood pressure.
  • Inflammatory changes in the eye.
  • Air bubbles in the eye after eye injections.

When Flashes and Floaters are Serious

Though the occasional flash or floater is normal, both flashes and floaters could be the result of a retinal tear or retinal detachment. A retinal tear is the result of a tear developing in the retina, which allows fluid to enter and begin to separate the retina from its nourishing, oxygen-providing blood vessels at the back of the eye. A retinal tear can progress into a retinal detachment, which is a sight-threatening condition. Both retinal tears and retinal detachment have similar symptoms.

The most common symptoms of retinal tear or detachment are:

  • Sudden increase in frequency of flashes of light.
  • Blurry vision.
  • Reduced vision.
  • Large floaters of sudden onset, or the sudden appearance of numerous small floaters like black pepper in your vision.

An additional symptom that could indicate retinal detachment is:

  • An opaque shadow or gray curtain that obstructs part of your vision.

Retinal tears and retinal detachment are painless. However, both constitute an emergency that could result in complete and permanent vision loss.

If you experience more flashes and floaters than usual or are experiencing flashes and floaters in addition to obstructed vision, call us to see one of our eye doctors at (770) 427-8111. We have after hours, on-call service as well for emergencies at the same number.

More About Retina Specialist Dhanu Meleth, M.D.

Known as Dhanu among his family and friends, Annal Dhananjayan Meleth was born in Kerala, India, but he admits with a chuckle it is difficult to answer the question of where he is from. This world traveler has lived in 26 different places. But most of his life was spent in India, England, Canada, and now the U.S. Dr. Meleth’s education and medical training have taken him on a meandering journey reaching from Québec, Canada, to Alabama, Washington, D.C., Texas, Australia, and now Atlanta, where his family resides. He spends some time every year teaching courses about medical and surgical management of diabetic retinopathy and provides charitable care for patients with advanced diabetic complications in various parts of the world. Read his full bio here. 

References and Additional Resources

The American Academy of Ophthalmology (AAO) is the world’s largest association of eye physicians and surgeons. It describes itself as a “global community of 32,000 medical doctors who protect sight and empower lives by setting the standards for ophthalmic education and advocating for our patients and the public.” Its website is a great resource to learn more about how to care for your eyes.

The American Optometric Association (AOA) describes itself as the leading authority on quality care and an advocate for our nation’s health, representing more than 44,000 doctors of optometry (O.D.), optometric professionals, and optometry students. 

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