Free · No sign-up · Works in the background
20-20-20 Timer
Every 20 minutes, it reminds you to look at something 20 feet away for 20 seconds. Press Start, keep this tab open, and get back to work.
Space starts and pauses. Esc skips a break. Want breaks without keeping a tab open? Peeka does this on your Mac.
How to use this timer
- Press Start. Leave this tab open. It keeps time in the background, even when you switch tabs.
- When you hear the chime, look away. Find something at least 20 feet (6 metres) away. A notification pops up too, if you allow it.
- After 20 seconds, a second chime. The next 20 minutes start on their own. Press Esc to skip a break.
What is the 20-20-20 rule?
Every 20 minutes, look at something 20 feet away for 20 seconds. It's a habit eye-care professionals suggest to anyone who spends hours looking at a screen.
California optometrist Jeffrey Anshel came up with it around 1991, while teaching office workers how to deal with computer eye strain. The usual advice then was a 15-minute break every two hours. He wanted something people would do sooner, without having to stop working.
Why 20 feet, and why 20 seconds?
When you look at something close, a small muscle inside each eye holds your focus tight. At around 20 feet (6 metres) it can let go almost completely. It's the same distance an eye chart treats as far away.
Twenty seconds is short enough that you'll actually do it. Use it to blink slowly, too: people blink far less often while staring at a screen, which is part of why eyes feel dry by the afternoon.
Does the 20-20-20 rule work?
It helps, as long as you keep doing it. In a 2023 study by Talens-Estarelles and colleagues, 29 people with eye-strain symptoms got 20-20-20 reminders on their laptops for two weeks. Their eye strain and dry-eye symptoms went down. One week after the reminders stopped, the improvement was gone.
So the rule is easy. Remembering it is the hard part, and that's what a timer is for.
This is a comfort habit, not a treatment. If your eyes hurt, your vision gets blurry, or you get regular headaches, see an optometrist.
Making the 20 seconds count
- No window? Look down the longest line you have: a hallway, the far corner of the room, the back wall.
- Let your eyes go soft. You don't need to stare at one point. Let the far-off view blur a little.
- Blink slowly, five or ten times.
- Make it a game. Spot something green. Count the windows you can see. The timer suggests something new each break.
- Don't reach for your phone. It's another screen at reading distance, which defeats the point.
Want a different rhythm, like Pomodoro? Try the break timer.
Peeka for Mac
A browser tab can't tell when you're busy. Peeka can.
Peeka is a tiny ghost that lives on your Mac's desktop and does this timer's job without a tab to keep open. It gets sleepier as your break gets closer, so the break never takes you by surprise.
- Waits until you stop typing, so it never cuts you off mid-sentence
- Hides during calls, presentations and screen shares
- Dims your screen for 20 seconds and gives you something to look at
- Naps when you step away, and starts fresh when you're back
macOS 14 or later · then $14.99 once, no subscription · See how it works
FAQ
Questions, answered.
Does the timer keep running if I switch tabs?
Yes. It keeps time against the clock, so it stays accurate in a background tab, and it remembers where it was if you reload. If your browser puts unused tabs to sleep to save memory, pin this tab.
How will I know it's break time?
You'll hear a soft chime, and you'll get a desktop notification if you allow them. If the tab is in front, a dim blanket slides over the page and counts the break for you.
Can I change the 20 minutes?
Use the break timer. It has presets for Pomodoro, 52/17 and others, and you can set any length.
Is the 20-20-20 rule a medical treatment?
No. It's a simple habit that many people find makes their eyes more comfortable. If you have pain, blurry vision or headaches, see an optometrist.
Does it work on my phone?
It runs in any modern browser, but phones lock their screens and pause web pages, so it works best on a laptop or desktop.
Is it really free?
Yes. No sign-up and no ads. It's made by Sameed, who also makes Peeka, a Mac app that does the same job without a browser tab.