What Causes Eye Floaters? Ophthalmologists Explain Those 'Cobwebs' You See Sometimes
They're usually harmless—but in rare cases, they can lead to vision loss.
Picture it: You're scrolling through Instagram, minding your own business, when all of a sudden a tiny speck floats across your field of vision. It definitely wasn't anything on your phone screen—so what the heck was it?
The likeliest scenario: You just spotted an eye floater—an often harmless quirk of being a human being with a pair of eyes. But it'd still be nice to know what exactly those little specks are, right? Health asked a few ophthalmologists (aka, eye doctors) to explain what exactly eye floaters are, what causes eye floaters, and when you might need to worry about them. Here's what you need to know.
What exactly are eye floaters?
So, eye floaters are basically specks or "cobwebs" that float around in your field of vision, according to the National Eye Institute (NEI). But they're not actually cobwebs; they crop up when the jelly-like substance filling the back of your eye, called the vitreous, beings to liquefy—a process that happens over time, Shameema Sikder, MD, an assistant professor of ophthalmology at Johns Hopkins University's Wilmer Eye Institute and director of the Center of Excellence for Ophthalmic Surgical Education and Training, tells Health.
Some people notice floaters very easily—that might be related to personality, your job, or simply how visually aware you are—and some people hardly ever notice them, Dr. Sikder says.
In general, floaters don't cause pain or discomfort, Doug Wisner, M.D., a cataract surgeon at Wills Eye Hospital in Philadelphia, Pennsylvania, tells Health. People often head to the doctor saying they're swatting at an insect that's not really there or say they see a speck in their vision, he says.
What causes eye floaters?
Really, floaters are part of the aging process, says Dr. Sikder. "A newborn has completely coherent jelly and someone who's 100 years old basically has this cavity filled with fluid because the jelly has liquefied," she says. "The transition is kind of like a lava lamp where the bits of jelly are floating around bathed in bits of liquid." And essentially, that's what a floater is: a glob or conglomeration of this jelly floating around in the fluid.
Trauma to the head or eye (like a sports injuries, or a car accident) can also precipitate floaters, as can health issues like diabetes or other eye conditions such as macular degeneration, adds Dr. Wisner.
And if you're very near-sighted (sometimes that means that the eyeball itself is a little longer than the average eyeball), your jelly could liquefy a little faster simply due to the anatomy of your eye, which means you might notice floaters earlier, says Dr. Sikder.
People who are pregnant, undergoing hormonal changes, can have some visual changes, too, and can sometimes have floaters, says Dr. Wisner.
So, do you need to worry about eye floaters?
Small floaters coming and going over time with no other symptoms are not abnormal or cause for alarm, says Dr. Wisner.
That said, if you notice a sudden onset of floaters or a floater persisting for over 24 hours, call the eye doctor for further evaluation, he says. Floaters of that magnitude, which occur with flashing lights or a "curtain" coming down on your vision could be an early sign of retinal detachment, says Dr. Sidker.
Retinal detachment happens when, as the jelly is floating around, it actually lifts off the surface of the retina—the wallpaper of your eye—releasing a little flash. If it pulls hard enough, your retina could tear or detach (this might look like a swarm of bugs with a flash of lights), Dr. Sikder says. Retinal detachments are serious conditions and should be treated immediately, says Dr. Sikder; if left untreated, they could lead to blindness.
How are eye floaters treated?
For most people, most of the time, there's no real treatment for floaters, says Dr. Sikder. There is the possibility of a retinal surgery to remove the jelly with lasers, essentially eliminating the floaters, but surgeries come with risks—and Dr. Sikder says ths one isn't necessary or worthwhile.
It is worthwhile, however, to have an eye exam. The American Academy of Ophthalmology recommends a baseline screening at age 40 (and earlier if you have eye disease risk factors such as diabetes or high blood pressure) then every few years, depending on risk factors, like diabetes or high blood pressure.
"An eye doctor can actually see the floaters that are there and determine exactly what may be causing them—whether they're just an age-related change, whether there is bleeding in the eye, a retinal issue, or whether there's something else entirely going on," says Dr. Wisner.
To get our top stories delivered to your inbox, sign up for the Healthy Living newsletter