The 20-20-20 rule: a small habit for tired eyes

Every 20 minutes, look at something about 20 feet (6 metres) away, for at least 20 seconds. That's the whole rule, and it's one of the simplest things you can do for eyes that spend the day on a screen.

Why screens tire your eyes

Reading a screen up close keeps the small focusing muscles inside your eyes working without a rest. People also tend to blink less while they concentrate, so the surface of the eye dries out faster than usual.

Eye-care organisations such as the American Academy of Ophthalmology call the result digital eye strain: eyes that feel tired, dry or sore, blurry vision after a long session, and sometimes headaches. It's common, and for most people it eases with rest.

Looking into the distance lets those focusing muscles relax, and a pause is a natural moment to blink. The 20-20-20 rule turns that into a habit with numbers that are easy to remember.

How to actually do it

1. Pick your far point in advance. A window, the end of a corridor, a picture across the room. If you have to search for one, you'll skip the break.
2. Let something else keep the time. Counting 20 minutes in your head doesn't survive a busy afternoon. A reminder that pops up at the right moment does.
3. Blink slowly a few times while you look away. It's part of the rest, not an extra step.
4. Don't worry about precision. Fifteen feet for twenty-five seconds is fine. The point is the regular change of focus.

Pulse has 20-20-20 reminders built in. You can snooze them up to three times, and if you already stepped away from your PC, Pulse counts that as your break.

Make your setup easier on your eyes

The rule works best alongside a comfortable setup:

• Keep the screen roughly an arm's length away, with the top of the display at or slightly below eye level.
• Match the screen's brightness to the room, and reduce glare from windows and overhead lights.
• Make text big enough to read without leaning in. Windows lets you change the scale in Settings → System → Display.

When to see someone

The 20-20-20 rule is a comfort habit, not a treatment. If your eyes stay sore, your vision changes, or headaches keep coming back, book an eye exam. An out-of-date glasses prescription is a common cause of screen fatigue, and it's an easy fix.