What Is the 20-20-20 Rule? Here’s How It Can Ease Digital Eye Strain

Screen time isn't going down anytime soon—and your eyes may be paying a price. Here's how the 20-20-20 rule could help.

Eye strain 101

There’s probably a lot of screen time in your life. After the last year or so, time spent staring at screens is only increasing.

Americans spend hours a day looking at screens, especially while at home.

“This year, that number rose with the pandemic, plus additional time spent on cellphones and other devices, leading to symptoms like headaches, as well as eye fatigue and strain,” says optometrist Rachael A. Wruble, president of the North Carolina Optometric Society and co-owner of Belmont Eye in Belmont, North Carolina.

One 2020 report from United Health Care found that more than 13 hours are spent on screens per day since Covid-19 emerged.

Still, hope exists for those glued to their screens: a simple technique that could relieve digital eye strain—the 20-20-20 rule. Here’s what you need to know about applying the rule, the benefits, and when it may be time to see a doctor.

The dangers of too much screen time

Digital eye strain

This condition is digital eye strain or computer vision syndrome (CVS).

“With more than two hours of screen time, you’re at risk for developing digital eye strain,” says Yos Priestley, assistant professor of ophthalmology at Duke University School of Medicine in Durham, North Carolina.

Estimates, like one from BMJ Open Ophthalmology in 2018, found that at least 50 percent of computer users had symptoms of CVS.

Today, the number may be higher. One 2021 study in Clinical and Experimental Optometry of almost 2,000 people suggests that more people experienced digital eye strain due to increasing time spent on devices during the pandemic, particularly during lockdowns.

The symptoms of digital eye strain include:

Why do screens have this impact?

Screens are hard on the eyes for a few reasons. One is the glare of the screen. The contrast puts a greater demand on eyes, and there’s less clarity of letters when read from a computer, Priestley says.

In other words, when you look at letters closely on a screen, they look fuzzy.

In addition, “we override our blink reflex on the computer, so blink rate decreases up to 50 percent, which contributes to dry eye,” she adds. Combined, these factors can lead to eye strain and dry eye.

The good news is that this process doesn’t cause permanent damage to the eyes, says Priestley, but it can make you feel terrible by the end of the day. Reducing screen time isn’t always possible, and that’s where the 20-20-20 rule comes in.

(Here’s how else digital screens affect the eyes.)

Close-up of a part of a man's face with glasseszagi89/Getty Images

What is the 20-20-20 rule?

You should follow the 20-20-20 rule multiple times per day to help decrease the risk of digital eye strain. According to the American Optometric Association (AOA), it involves three easy steps:

  • Every 20 minutes take a 20-second break to look at something 20 feet away.

What are the benefits of the 20-20-20 rule?

Your eyes don’t want to always focus on things up close or at mid-distance.

“The natural state or posture of eyes is looking far away,” says Wruble. And so, if eyes always focus at one distance, they grow tired and weary.

“The 20-second break allows eyes to relax in their normal posture,” she explains.

So, no, adds Wruble, the idea is not to look away from your computer and at your cellphone. (Though it may be tempting.)

Research, such as a 2020 study in African Vision and Eye Health, found that for people who have dry eyes because of excess screen time, practicing the 20-20-20 rule improves symptoms but wasn’t powerful enough to completely reverse CVS, suggesting that you’ll have to take a few extra steps for full relief. (More on that in a minute.)

How to do the 20-20-20 rule

It might be tough to remember to take these breaks if you’re multitasking or especially busy, so try scheduling them.

Wruble suggests setting a timer (as a pop-up on your computer, a recurring alarm on your phone, or via an app) that will tell you to take the break.

To do it, just look off in the distance, like out of a window. You don’t have to measure 20 feet—you just need some distance.

In addition to taking a break for your eyes, Priestley also suggests doing a couple of “hard blinks.” (Blink-blink-squeeze.)

“This motion gets the oil glands that line the eyelids to release oil. The oil layer helps decrease the evaporation of tears when you look back at the screen,” she says.

After those blinks, you can turn your attention back to your screen. If you’re having issues with dry eyes on account of CVS, you might also want to use preservative-free artificial tears to lubricate your eyes a couple of times per day.

Make your computer station eye-friendly

Along with the 20-20-20 rule, there are other things you can do to decrease your risk of computer vision syndrome. Here are tips for setting up your screen:

  • Away from your face: Ideally, set your computer screen arms-length from your face, says Priestley.
  • Slightly below eye level: Place your screen so you need to look down about 10 to 15 degrees, suggests Priestley.
  • Avoid glare: Are there bright windows around you? Adjust your screen’s brightness to match the brightness of the room. (For instance, bring the screen brightness down in a dim room.) This helps your eye’s ability to focus. You can also close blinds and drapes or move lights around if glare is a problem, says Wruble.
  • Sit up: Wruble advises finding a chair that provides back support; try to maintain good posture as you sit.

When the 20-20-20 rule doesn’t work

The 20-20-20 rule is a handy practice that can help prevent eye strain from digital devices. However, it can’t fix everything.

If you’re noticing worsening eye issues or you have to use artificial tear eye drops several times per day, see an optometrist or ophthalmologist to get your eyes checked, recommends Priestley.

You may need prescription glasses or an adjustment to your current prescription. Your glasses may be better suited for driving or up-close reading but not computer work. Getting an anti-reflective coating on your glasses can also help with computer glare.

Next, check out the signs you need to see an eye doctor.

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Jessica Migala
Jessica Migala is a freelance health and fitness writer with more than a decade experience reporting on wellness trends and research. She's contributed to Health, Men's Health, Family Circle, Woman's Day, and O, The Oprah Magazine, among other publications. Jessica lives with her husband and two young sons in the Chicago suburbs.