Does the 20-20-20 rule work? A small study put it to the test
· Updated · 4 min read · 2 studies cited
The 20-20-20 rule is a reminder to look away from your screen: every 20 minutes, look at something about 20 feet away for 20 seconds. In one small study, people reported less eye strain while reminders were on (Talens-Estarelles et al., 2023). The study did not prove that the reminders caused the change or that these numbers are the best ones to use.
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Every 20 minutes, look away from your screen.
Choose something about 20 feet away, roughly six meters.
Look at it for 20 seconds.
These are the numbers in the familiar 20-20-20 rule. The study did not test whether a different interval, distance or duration worked better.
The study
Researchers followed 29 computer users who already had eye strain (Talens-Estarelles et al., 2023). First came two weeks without reminders. Next came two weeks of software reminders to follow the rule, then one week after reminders stopped. The same people completed every stage. They answered questions about their symptoms and had eye tests.
Read figure details
The study followed 29 computer users who already had eye strain.
Researchers first tracked two weeks without reminders. Next came two weeks of 20-20-20 reminders, then one week after the reminders stopped.
People reported fewer symptoms during reminders. It was unclear whether that improvement lasted after the reminders stopped.
Tests for signs of dry eye did not improve. Most other eye tests did not change either, but one focusing test improved. This was accommodative facility, a measure of how readily the eyes change focus.
All 29 people followed the same sequence. There was no separate group for comparison, and the study did not test different break schedules.
People reported fewer eye strain and dry eye symptoms during reminders. It was unclear whether that improvement lasted after reminders stopped. Here is how the authors summed it up, using DES for digital eye strain:
“The 20-20-20 rule is an effective strategy for reducing DES and dry eye symptoms, although 2 weeks was not enough to considerably improve binocular vision or dry eye signs.”
Tests for signs of dry eye did not improve. Most other eye tests did not change either, but one focusing test did improve (Talens-Estarelles et al., 2023). That test measured accommodative facility: how readily the eyes change focus. Feeling better and changes on an eye test are different findings.
What it tells us, and what it doesn't
Everyone followed the same sequence. There was no separate group to show what would have happened without the reminders. That makes it hard to separate the effect of reminders from other changes, such as people paying more attention to their eyes. The study was also small and short.
It doesn't show that breaks treat dry eye or improve vision, and it isn't a reason to skip an eye test. If your eyes are persistently sore or dry, or your vision has changed, see an optometrist or doctor.
The part about reminders
The symptom improvement happened during the reminder period. After the reminders stopped, the results were less clear. That raises a useful question about keeping up a habit, but it does not prove that switching off reminders caused symptoms to return.
The same question comes up in research on sitting. A 2017 review of 17 trials looked at apps, prompting software and wearables designed to reduce sitting (Stephenson et al., 2017). On average they cut sitting by about 40 minutes a day in the short term. Beyond six months, the effect had nearly vanished.
“Effectiveness appeared most prominent in the short-term and lessened over time.”
These studies leave questions about how long changes last. If you use a reminder, choose one that fits your day and adjust it when you start ignoring it. That is a practical suggestion, not a result tested by this eye study.
Why the numbers are 20, 20 and 20
The three 20s are easy to remember. This study tested them together; it did not compare different timings or distances. It cannot tell us whether, for example, looking away every 25 minutes would work better or worse.
In a real office, 20 feet is roughly the far side of a room, the end of a corridor, or anything outside a window. If you can't see that far from your desk, looking as far away as you can is a sensible approximation, and a short walk gets you the distance view for free.
How to use the rule
- Every 20 minutes or so, look at something far away: out of a window, down a hallway. About 20 feet, or 6 meters, is enough.
- Hold it for about 20 seconds, and let yourself blink.
- If reminders help you remember, choose one you can comfortably fit into your day.
- Pair it with a movement break when you can. Standing up and walking away from the screen changes where you're looking anyway.
DeskBreak's 1-Minute Eye Break is a guided version: a look into the distance, a few slow blinks, and a moment away from the screen. It's for comfort during screen work, not a treatment for any eye condition.
If you try it, notice whether the reminder fits your day and how your eyes feel. Your experience can guide your routine, but it is not a diagnosis or a test of whether a treatment works.
Try the 1-Minute Eye Break
A distance look, some slow blinks, a moment away from the screen. For comfort, not a treatment for eye conditions.
References
- Talens-Estarelles, C., Cerviño, A., García-Lázaro, S., Fogelton, A., Sheppard, A., & Wolffsohn, J. S. (2023). The effects of breaks on digital eye strain, dry eye and binocular vision: Testing the 20-20-20 rule. Contact Lens and Anterior Eye, 46(2), Article 101744. https://doi.org/10.1016/j.clae.2022.101744
- Stephenson, A., McDonough, S. M., Murphy, M. H., Nugent, C. D., & Mair, J. L. (2017). Using computer, mobile and wearable technology enhanced interventions to reduce sedentary behaviour: A systematic review and meta-analysis. International Journal of Behavioral Nutrition and Physical Activity, 14(1), Article 105. https://doi.org/10.1186/s12966-017-0561-4