The 20-20-20 rule means looking away from close work every 20 minutes, at something about 20 feet (6 metres) away, for 20 seconds. It's an easy reminder to pause. Research on the exact schedule is mixed, so use it as a routine, without treating a completed countdown as proof of healthier eyes.
A break notification appears while you're reading a document. You stop typing, then spend the countdown reading a message on your phone. The timer has worked; the intended change of viewing distance hasn't happened. Before choosing an app or adjusting its settings, decide what you'll actually look at when the reminder arrives.
Choose the view before you choose the timer
The American Optometric Association's reminder gives the familiar three numbers: 20 minutes, 20 seconds, 20 feet. In a room measured in metres, the distance is approximately six metres. It doesn't mean 20 metres, and the last number has nothing to do with a 20/20 visual-acuity test.
Pick a real object you can see from your desk: a tree through a window, a building across the street, or the far end of a long room. You don't need an interesting view. You do need a place that doesn't pull you into more reading. Looking at text on the adjacent monitor or picking up a phone keeps the task close.
A small office may not offer six metres of clear space. Look for a safe view outside or plan to step into a suitable open area. If neither is available, taking a pause from the task is still a practical choice, but describe what you did honestly. A two-metre wall isn't six metres away because a timer says the break is complete.
Don't spend the entire pause checking how many seconds remain. Let the reminder indicate when to return, while your attention stays off the displays. This is why we recommend sorting out the view first: it removes a decision from the moment when you're most likely to dismiss the prompt.
The studies don't settle the exact numbers
One study of 29 symptomatic computer users reported reduced symptoms after two weeks of reminders, without corresponding improvements in measured ocular-surface or tear-film signs. The symptom improvement wasn't maintained a week after reminders stopped. It tested a reminder routine, not Have You Rested?.
A separate experiment with 30 young participants found no significant symptom benefit from scheduled 20-second pauses during a demanding 40-minute tablet reading task. Different tasks and study designs limit direct comparison; neither establishes a universally optimal schedule.
Our recommendation is to use the rule as a memorable starting point if it helps you interrupt long stretches of close work. The evidence doesn't justify promising that precisely following it will cure dry eye, prevent myopia or reverse a vision problem. It also doesn't justify calling every short pause useless. Those are broader claims than these studies can answer.
Keep the distinction between behaviour and health clear. “I looked away when prompted” is something you can check. “My eyes are now protected” isn't something a notification, a webcam or an app score can establish. If symptoms persist, discuss them with an eye-care professional rather than making the countdown stricter.
A checklist for your next work session
- Choose your distant viewing target before opening the document or editor.
- Set a reminder for 20 minutes and a pause for 20 seconds. Start with one reminder system.
- When it appears, stop reading, put down the phone and look toward the target.
- Return after the pause. Leave longer breaks in your day; a brief eye break doesn't replace them.
- At the end of the session, check whether you actually took the pauses, then fix the one obstacle that kept recurring.
For example, during a 60-minute work block, reminders set from the start would fall around minutes 20 and 40, with another at the boundary. That's an illustration of the schedule, not a prescription for everyone or a promise about an app's elapsed-work calculation. Sleep, temporary pauses and app settings can change when its next prompt appears.
For a long meeting, think about a suitable moment to look away while continuing to listen, if the task allows it. If you're presenting a chart or handling something that needs uninterrupted visual attention, take the pause when it is safe to do so. You don't need to stack missed breaks into a punishment after the call.
Try the routine with the work you normally do. A schedule that looks neat on a weekend test may be awkward during calls. Change one thing at a time, such as the viewing target or the reminder's placement, so you can tell what helped. This is a test of whether the routine fits your day, not a medical experiment.
Using a reminder on an Apple silicon Mac
Have You Rested? runs on Apple silicon Macs with macOS 13 or later. The Free timer provides 20-minute eye-break intervals and 20-second pauses, with a 15-second warning. It also includes longer breaks and blink/posture nudges. Follow the Mac eye-break setup guide to install it and check that reminders are enabled.
Start with timed breaks if you simply need a prompt. A countdown can finish while you keep reading another screen. Pro's camera-assisted verification can help check whether you look away, but it cannot measure a six-metre viewing distance or evaluate eye health. The choice is about following the pause, rather than proving a medical result.
If you want to use no camera at all, follow the camera-free setup instructions. Privacy Mode avoids continuous monitoring, while Pro can still use the camera for an individual verified break if macOS permission is allowed. Denying camera access in System Settings makes the no-camera choice explicit, including during the trial.
Turning a screen off is a separate decision. It may remove the temptation to read, but a dark display doesn't tell you whether the Mac is asleep or its session is locked. Our guide to display sleep, system sleep and locking explains that distinction. You don't need to change power settings just to look away.
What to do when the routine isn't enough
If every reminder gets dismissed, check the practical reason first. Is the window out of sight? Is the phone still on the desk? Did you enable two apps that interrupt each other? Fix that specific obstacle before adding more alerts. A reminder you can act on is more useful than several prompts you automatically close.
If you're taking the pauses but still find screen work uncomfortable, don't interpret that as a failure of willpower. The rule doesn't explain every cause of discomfort. Bring the pattern to an eye-care professional: what task you were doing, how long it lasted and whether the discomfort continues after stopping. A timer cannot diagnose the cause.
For the product's timer and verification options, see the current feature overview. Choose a setup that helps you leave the close task alone for a moment. The useful outcome to track is whether you changed what you were looking at, not whether every countdown ended perfectly.
Questions about the 20-20-20 rule
Is 20 feet the same as 20 metres?
No. Twenty feet is about six metres. The distance is a reminder to look beyond close work; 20 metres is a different distance.
Can I check my phone during the pause?
That keeps you reading at close range. Put it down and look toward your distant target if you're following the rule's intended routine.
Does the rule treat dry eye or prevent myopia?
The evidence described here doesn't establish those claims. Use the routine as a reminder, and ask an eye-care professional about persistent symptoms or an existing condition.
Do I need camera verification?
No. A timed reminder can be enough. Verification is optional assistance with looking away, and it cannot certify the distance or a health benefit.
If you'd like a timer for this routine, download Have You Rested? and begin with the Free timed breaks.