How All That Screen Time Actually Affects Your Eyes

The 20–20–20 rule can help

The second I woke up this morning, I picked up my phone and checked my email before catching up on Instagram and Twitter. I spent the next eight or so hours switching between browser tabs for Gmail, Zoom, and Google Docs to work. Any time I took a break, I was back scrolling through social media or reading a few chapters of an e-book on my iPad. When I wrapped up work, I did an hour-long workout using the Nike Training Club app on my phone. Before bed, I watched two episodes of Schitt’s Creek.

Sounds pretty normal, right? Since lockdown started, 59% of adults admit to spending more time on their computers and mobile phones, and 55% say they watch more TV, a poll of over 1,000 Americans found in July.

Aren’t your eyes exhausted?Just two consecutive hours staring at a screen puts you more at risk for eye strain, dry eyes, headaches, and blurred vision, according to the American Optometric Association. Most of these problems are temporary, though, says William Reynolds, O.D., president of the American Optometric Association and CEO of Eye Care Center Optometrists PSC in Richmond, KY. “If you get away from the computer and relieve that strain, usually, the problems go away,” he explains.

Given how much screen time people are currently using to learn, exercise, socialize, and date, as well as work, they clearly aren’t getting away from their computer. And all that cumulative screen time can have long-term, detrimental effects on your vision.

Picture how you use your screens: Are you hunched over a laptop? Holding your phone right up to your face? The closer you are to digital devices, the harder your eyes have to work — and prolonging that position can cause myopia, a condition in which the eye becomes elongated, making close objects appear clear but objects further away seem blurry, explains Reynolds. High amounts of myopia can significantly increase the risk of major eye issues like retinal tearing, glaucoma, or cataracts, according to research published in the journal Progress in Retinal and Eye Research.

It’s something doctors are particularly concerned about in children, whose eyes are still developing (especially as they engage in remote learning), but it can happen in adults as well. In fact, over half of the world’s population will be myopic by 2050, a 2015 report in the journal Ophthalmology found. “Usually, if people are going to develop myopia, they’re going to develop it in the first 20 years of life,” says Richard Davidson, MD, ophthalmologist with UCHealth Sue Anschutz-Rodgers Eye Center. “But I do worry that people spending the majority of their time using their eyes at within 12 to 15 inches could accelerate and increase the magnitude of myopia.”

That kind of close-up focus — just imagine the intensity at which you stare at an Excel spreadsheet for hours — is also a major cause of dry eyes. “When we look at a screen, we tend not to blink as often,” says Davidson. Research shows that a healthy, normal blink rate is between 12 and 15 times per minute; while staring at your computer, tablet, or smartphone, that rate can drop as low as six times per minute.

Blinking is essential, because it spreads a film of liquid from your tear ducts over the ocular surface. “Think of your eye like an ice skating rink that’s being skated on. Those blinks kind of act like a Zamboni,” Davidson explains. “We need them to lubricate and resurface the cornea.”

Chronically dry eyes can cause long-term damage to the cornea and other tissues. The drier your eyes get while trying to stay attentive during endless Zoom calls, “the more inflammation occurs on the ocular surface, which reduces tear output, and kicks off a vicious cycle of dryness that can become sight-threatening,” Davidson says.

There’s also the issue of blue light, a type of short-wavelength light commonly emitted by digital devices. Studies have shown that exposure to this kind of light can disrupt sleep (denying our eyes yet another opportunity to lubricate and replenish), and some research has identified it as a risk factor for macular degeneration, which can lead to blindness.

“Blue light exposure may increase the risk of macular degeneration and does contribute to eye strain,” says Davidson. The macula is an oval-shaped, pigmented area near the center of the retina; it provides the central vision we need for seeing detail. “We know that blue light can affect the pigmentation of the macula, which is concerning,” adds Reynolds. “Anything that affects the function of the macula would decrease our central vision.” Reynolds says that, clinically, he has seen macular degeneration occurring at earlier ages than in the past.

Still, there’s been no conclusive evidence to link the two — yet. “We need research to determine whether blue light affects strain, and whether cutting down on blue light helps with strain,” says Davidson. “But blocking that light, whether with a blue light-blocking screen or glasses, definitely doesn’t hurt.”

As scary as the effects of too much screen time sound, they are pretty easily avoided. While things like artificial tears and blue light-blocking gear may help, most eye doctors — including Davidson and Reynolds — recommend implementing the ridiculously easy 20–20–20 rule, which encourages you to look away from your computer every 20 minutes at an object that is about 20 feet away for a full 20 seconds. Not only does that give your eyes a focusing break, it encourages blinking, and gives your eyes a rest from those blue light wavelengths. If you really struggle to tear yourself away from digital devices, set an alarm to snap yourself out of your staring contest with your screen.

Not only will your eyes benefit from the break, but your brain will be better off, too — no one’s ever benefited from doomscrolling through Twitter or falling into a YouTube rabbit hole for more than 20 minutes.

Ashley Mateo has over a decade’s worth of experience covering fitness and health for publications including the WSJ, Men’s Journal, SELF, and more. @ashleymateo

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