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20-20-20 rule timer for eye strain
A free 20-20-20 timer that reminds you every 20 minutes to look 20 feet away for 20 seconds, with sound and desktop notifications.
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A screening aid, not a diagnosis. Screens, lighting and distance affect results. If something looks wrong, or your vision changes suddenly, see an eye-care professional. Medical disclaimer
How to use the timer
Press Start and keep this tab open while you work. Every 20 minutes the timer chimes and, if you allow it, shows a desktop notification. Look at something about 20 feet (6 metres) away for 20 seconds and blink fully a few times. The timer then counts the next 20 minutes on its own and tallies your breaks for the day.
You can change the interval, mute the chime, or pause the timer for meetings. Your settings are saved in this browser.
Why screens tire your eyes
Looking at something close keeps the focusing muscles inside your eyes working, and people blink much less when concentrating on a screen. Hours of that leads to tired, dry, sore or blurry eyes and headaches, often called digital eye strain or computer vision syndrome.
Other habits that help
- Keep the screen about an arm’s length away, slightly below eye level
- Match screen brightness to the room and cut glare
- Enlarge text instead of leaning in
- Use lubricating drops if your eyes feel dry
- Get your eyes checked; many people over 40 need a separate prescription for screen distance
Questions people ask
Does the 20-20-20 rule really work?
It gives your focusing muscles regular rests and reminds you to blink, which eases symptoms of digital eye strain for many people. It does not prevent or cure nearsightedness in adults.
What if I can't see 20 feet away?
Look out of a window or at the far side of the room. The point is to relax focus by looking into the distance.