LookAwayThe 20-20-20 rule
Every 20 minutes, look at something 20 feet away for at least 20 seconds. A tiny reset for eyes that spend all day up close.
- 20 minutes of normal work
- 20 feet into the distance
- 20 seconds to let your eyes rest
20 minutes of focus, then a 20-second break. We'll notify you.
The simple version
What is the 20-20-20 rule?
The rule was coined by optometrist Jeffrey Anshel in the early 1990s, when he was consulting for companies full of early computer workers with end of day headaches. The standard advice of the time was to take a 15-minute break every two hours. But that wasn't matching how fast visual fatigue builds in reality. He needed something people would remember without thinking, and three twenties stuck.
Each 20 has a job:
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20 min
Break the strain cycle
A quick pause every 20 minutes interrupts close-up effort before it builds into tired, dry, or unfocused eyes.
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20 ft
Let near-focus muscles relax
At about 20 feet, your eyes no longer work as hard to focus up close, giving the muscles around the lens a chance to relax.
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20 sec
Give your eyes time to reset
Twenty seconds lets your focusing muscles release and gives you time for a few full blinks to refresh your protective tear film.
A clear-eyed look
Does the 20-20-20 rule actually work?
The rule is more popular than the evidence behind it. Anshel himself has said the numbers were chosen to be memorable, not because a lab derived them. So it's worth separating what's proven from what's convention.
The exact numbers aren't magic. In a 2023 study in Optometry and Vision Science, researchers had people complete a demanding 40-minute reading task with 20-second distance breaks every 5, 10, 20, or 40 minutes, and found no significant difference in eye strain symptoms between any of the schedules. It's one small, short study, but it tested the "every 20 minutes" claim directly, and the magic interval didn't appear.
Regular breaks, though, do seem to help. A 2023 trial in Contact Lens and Anterior Eye installed webcam software on the laptops of 29 symptomatic computer users to detect screen habits and nudge 20-20-20 breaks for two weeks. Participants took more breaks, and their digital eye strain and dry eye symptoms improved. Just as telling: one week after the reminders stopped, the improvements faded. The breaks worked, and nobody kept taking them without the reminder. (Again: small sample, short duration. The evidence base here is thinner than the rule's fame suggests.)
The underlying physiology is solid. You blink far less at a screen, a classic New England Journal of Medicine study measured 22 blinks per minute relaxed versus 7 at a display. This dries the tear film, and hours of continuous near focus genuinely fatigue the eye's focusing system. Distance breaks address both, which is why the American Optometric Association recommends the rule and the American Academy of Ophthalmology recommends regular screen breaks.
The practical verdict
The numbers are a memorable convention. What the evidence supports is the habit: regularly looking far away and blinking. The 20-20-20 rule survives because it's the easiest version of that habit to remember. If your room is 15 feet deep or your break runs 30 seconds, you're still doing it right.
This page summarizes published research; it isn't medical advice. If eye strain persists or comes with vision changes, see an eye-care professional.
The hard part
Why nobody sticks with it (and how to)
The 20-20-20 rule doesn't fail because it doesn't work. It fails because remembering to look away every 20 minutes, all day, is exactly the kind of thing a brain in deep focus is worst at. That's the quiet finding of the two-week study above: symptoms improved while the reminders ran, then regressed within a week of them stopping.
So don't rely on memory:
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01
The timer on this page works. Keep the tab open and turn on the chime.
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02
Phone alarms or a recurring calendar nudge work, if you'll actually obey them after the tenth one.
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03
A sticky note on the monitor bezel works for some people, for about a week.
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04
Or make it automatic: LookAway lives on your Mac and runs the break for you every 20 minutes. Smart Pause detects calls, presentations, and active typing, then waits so a break never lands mid-meeting.
Good to know
Common questions
Often, yes. Especially, when the headaches come from digital eye strain. Fatigued focusing muscles and reduced blinking can trigger late-day, brow-region headaches, and regular distance breaks address both. If headaches persist despite breaks, or come with vision changes, see an eye-care professional. Screens are only one of many possible causes. (Curious how at-risk your habits are? Try our eye strain risk calculator.)
No. 20 feet just approximates "far enough that your focusing muscle fully relaxes." Looking out a window is ideal; farther is fine. In a small room, use the longest sightline you have: a doorway, a hallway, the far corner. Partial relaxation still beats twenty more minutes of locked near focus.
It's a break schedule tuned for eyes, and packaged so you'll remember it. A coffee break spent looking at your phone doesn't relax your focusing system, because your eyes never leave near focus. The value is in the distance gazing and the blinking, not the break itself.
The logic applies to any sustained close focus: books, tablets, consoles. For kids the case is arguably stronger. Long hours of near work are linked to myopia progression, so building the look-far habit early is worthwhile. For gaming, tie breaks to natural pauses: match ends, loading screens, respawns.
The evidence is weak. A 2023 Cochrane review of 17 randomized trials found blue-light-filtering lenses probably make no difference to eye strain from computer use. Screen strain comes mostly from focusing effort and reduced blinking, not blue light. Which is why breaks help and special lenses generally don't.
Yes — that's what LookAway is: a Mac app that runs 20-20-20 breaks for you and pauses itself when you're on a call or presenting. One-time purchase, with a free trial.
Remember less. Look away more.
LookAway makes the 20-20-20 habit automatic, then gets out of the way when you're in a call, presenting, or deep in focus.