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How to prevent eyestrain with the 20-20-20 rule

Use this simple optometrist-endorsed tip to keep your eyes fresh.

Glasses that block blue light can help prevent eye strain, but there's a totally free way, too.
Angela Lang/CNET

If you're a veteran desk job worker, you're probably too familiar with the way your eyeballs feel after a long day. If you're new to the computer work lifestyle, you're probably thinking (if not screaming), "What is going on with my eyes?!?"

Welcome to Club Eyestrain (it's not a fun club). Eyestrain can induce all sorts of unpleasant feelings, such as burning, itching, dry eyes, watery eyes, headaches, blurry vision, double vision, tiredness and difficulty focusing. 

Fortunately, there is a way to reduce your chances of entering the eyestrain domain, and it's surprisingly simple. 

It's called the 20-20-20 rule, and the American Academy of Ophthalmology (AAO) and the American Optometric Association (AOA) both endorse it as a way to prevent screen-related eyestrain. 

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What is the 20-20-20 rule? 

Every 20 minutes, take a 20-second break from looking at your screen and look at something 20 feet away. See? Simple. 

Only, it's really easy to forget to actually do it. Setting a timer on your phone for every 20 minutes or using an app can help, but in an 8-hour work day, that comes out to 24 eyeball breaks. That's a lot, and if you have trouble getting into deep focus mode, looking away every 20 minutes can impede your workflow. 

Here are some ways to adapt the 20-20-20 rule if it's just not working out for you: 

  • Make it 40-40-40. This may not work quite as well as the 20-20-20 rule, but offers a good balance between focus and preventing eyestrain. 
  • Practice the 20-20-20 rule for half of the day. Pick morning or afternoon and commit to taking all of your breaks. You can slowly add more breaks as you get better at reestablishing your focus. 

The 20-20-20 rule for preventing eyestrain.

American Optometric Association

What should you look at? 

Chances are, you probably can't accurately measure a 20-foot distance without a measurement tool. It's pretty easy to estimate, though: If you're a 6-foot person, look at something that seems to be three of your body lengths away. If you're a 5-foot person, look at something about four body lengths away. 

Alternatively, you can just look out of your window or at something in the distance. Focusing on a tree or something else outdoors is a good way to give your eyes a break. 

The timing is more important than the distance, because the key is to give your eyes a chance to fully relax, multiple times per day.


Staring at your screen for too long can do a number on your eyes.

Getty Images

Other things you can do to prevent eyestrain

If the 20-20-20 rule isn't enough to keep your eyes from burning, itching or tiring out, try these other tips for reducing the strain on your eyes: 

  • Reduce glare on your computer screen by adjusting your settings or using a matte filter (lots of computers come with matte screens, these days, too).
  • Reduce the contrast and brightness on your computer screen.
  • Position your computer screen so that it's 24 to 26 inches away from your face, and so that your eyes point down slightly, rather than up or straight. 
  • Wear glasses that block blue light or get a blue-light blocking filter for your screen.
  • Permanently enable night mode on your device so it emits gentler, yellower light.

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The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.