The 20-20-20 Rule for Eye Strain: What It Is and Does It Work?

What is the 20-20-20 rule?

The 20-20-20 rule is a simple break routine for screen users: every 20 minutes, look at something at least 20 feet (6 meters) away for at least 20 seconds. You can start the timer at the top of this page right now and let it remind you while you read.

You may also see it written without hyphens as the 20 20 20 rule, or searched as "20 20 20 rule eyes". It is the same habit.

The American Academy of Ophthalmology recommends it for digital eye strain. The American Optometric Association gives the same rule, and CCOHS says eye specialists recommend it.

The easiest way to follow it is to let something else keep time. A 20-20-20 rule timer, like the one embedded above or the free eye break timer in its own browser tab, prompts you when it's time to look away.

Why does looking into the distance help?

Looking at something close takes muscular effort. CCOHS explains the two processes involved: accommodation, where the eye changes the shape of its lens to focus, and convergence, where both eyes turn inward toward the nose. The closer the object, the harder both systems work.

Looking far away lets both relax. CCOHS notes that looking at far distances does not cause eyestrain; it is the effort of focusing up close for long periods that does.

The second benefit is blinking. The AAO reports that people blink about 15 times a minute normally, but only about 5 to 7 times a minute when using screens. A pause from the screen is a natural moment to blink fully and re-wet the eye surface.

How do you do the 20-20-20 rule properly?

1. Set a timer for 20 minutes. Without a reminder, most people forget within an hour. The timer at the top of this page counts down for you.
2. When it goes off, look away from the screen at something at least 20 feet away: out of a window, down a corridor, or at the far wall of a large room. OSHA's example is a clock on a wall 20 feet away.
3. Hold your gaze there for at least 20 seconds. Let your eyes relax rather than staring hard.
4. Blink a few times before you look back.
5. Reset and repeat.

If your workspace is small, look at the furthest thing you can see. CCOHS adds a lighter version for between breaks: every few minutes, look away from the screen for a few seconds, look around, focus on distant objects and blink several times.

Does the 20-20-20 rule actually work?

This is where it gets more honest than most articles. The rule is widely recommended, but the research behind the specific numbers is thin, and the two best-known studies point in different directions.

Study	Who and what	Main findings
Talens-Estarelles et al., 2023, Contact Lens and Anterior Eye	29 symptomatic computer users; software reminders based on the rule for 2 weeks, then 1 week without	Digital eye strain and dry eye symptoms decreased with reminders, but the improvement was not maintained one week after stopping. No change in binocular vision measures except accommodative facility. No change in tear film or ocular surface signs.
Johnson & Rosenfield, 2023, Optometry and Vision Science	30 young subjects; 40-minute tablet reading task with 20-second breaks every 5, 10, 20 or 40 minutes (no break)	Symptoms rose after every trial, but break schedule had no significant effect on symptoms, reading speed or accuracy.

Johnson and Rosenfield note in their abstract that there is relatively little peer-reviewed evidence for the rule. Their own results did not support 20-second scheduled breaks as a therapy for digital eye strain. The Talens-Estarelles team concluded the rule was an effective strategy for reducing symptoms, while noting two weeks was not enough to change binocular vision or dry eye signs.

How should you read these results?

Both studies were small and short. They also tested different things: real computer users over two weeks versus a single 40-minute lab task. A fair summary is:

• The rule seems to help some people feel better while they keep doing it.
• There is no strong evidence that the exact 20/20/20 numbers are special.
• The benefits seen were in symptoms, not in measurable eye changes.

Since the rule costs nothing and has no known downside, it remains a reasonable habit. Just don't rely on it as the only fix.

What else should you do besides the 20-20-20 rule?

The same sources that recommend the rule also recommend longer breaks and setup changes.

• Longer breaks. The AOA suggests resting the eyes for 15 minutes after two hours of continuous computer use. HSE says short, frequent breaks are better than long, infrequent ones, for example 5 to 10 minutes every hour, and that breaks should let you get up and move.
• Screen position. About an arm's length away, slightly below eye level. See how high your monitor should sit.
• Brightness and glare. Match screen brightness to the room and keep windows and lamps from reflecting off the screen.
• Eye care. Uncorrected vision problems make strain worse, according to the AOA. Keep your prescription current and tell your eye doctor about your screen work.

Our full list of remedies for eye strain covers all of these in detail.

How do you make the habit stick?

Most people know the rule and few follow it. A few things help:

• Use an automatic reminder. A timer that prompts you is more reliable than willpower. Break-monitoring software is recognized by HSE as a way to remind users, though it notes employers still need to plan work so breaks happen.
• Tie it to something you already do. Look out of the window every time you send a message or finish a call.
• Pair it with a stretch. Every second or third reminder, stand up. That also covers the movement breaks recommended in our guide to correct sitting posture.
• Arrange your desk for distance. Position your desk so a window or long view is to the side of your screen. This also helps with glare, since OSHA recommends placing the monitor perpendicular to windows.

How does the 20-20-20 rule fit into workplace break policies?

For employers, the rule is a useful message for staff but not a complete break policy. In Great Britain, HSE says the law requires employers to plan work so DSE users get breaks or changes of activity. There is no legal guidance on exactly how long or how often, because it depends on the work.

HSE's practical points for a policy:

• In most jobs, natural changes of activity, such as meetings or phone calls, provide breaks. Where a job has none, employers should plan rest breaks.
• Ideally, users should be able to choose when to take breaks.
• Breaks should let people get up and move around, or at least stretch and change posture.

A sensible policy pairs short visual breaks like this one with longer movement breaks every hour, and includes eye tests for screen users who ask for them. HSE says employers in Great Britain must provide those tests on request.

Is the 20-20-20 rule useful for children or for myopia?

The guidance and studies cited here are about digital eye strain in adults. We have not covered myopia control or children's screen use, because that is a different clinical question. Ask a pediatric eye care professional for advice on children's eyes.

This article is general information, not medical advice. If you have persistent eye pain, redness, blurred vision or light sensitivity, see an optometrist or ophthalmologist.

Next steps

Remote workers can pair it with a quick home office ergonomics check.

Start the 20-20-20 rule timer at the top of this page or open the eye break timer in its own tab, leave it running for a full workday, and note whether your eyes feel different by late afternoon. Then check your screen position and lighting with our guide to workstation ergonomics.