20-20-20 Rule Timer: Free Eye Break Reminder for Screen Work

What is the 20-20-20 rule?

Every 20 minutes, look at something at least 20 feet (about 6 meters) away for at least 20 seconds. The American Academy of Ophthalmology and the American Optometric Association both recommend it to ease digital eye strain.

The idea is simple. When you look at a screen up close, the muscles that focus your eyes work continuously. Looking far away lets them relax for a moment, and a 20-20-20 rule timer makes sure the moment actually happens. Our guide to the 20-20-20 rule goes into the reasoning and the evidence.

How does this 20-20-20 rule timer work?

The timer counts down 20 minutes of work. When the time is up, it plays a soft chime and, if you have switched them on, sends a desktop notification so you see it even if you're in another window. It then counts down a 20-second break: your cue to look into the distance before carrying on. The next 20 minutes start automatically.

You can also turn on optional stretch prompts. These add a short movement suggestion to your breaks, such as rolling your shoulders or standing up, so you move your body as well as rest your eyes.

Step	What you do
Start	Press start; turn on desktop notifications if you want them
20 minutes	Work as normal while the timer runs
Reminder	A chime (and a notification, if enabled) tells you it's time to look away
20 seconds	Look at something at least 20 feet (6 m) away
Optional	Follow the stretch prompt if you turned them on

Can I customise the eye break timer?

Yes. The settings panel lets you change how often you are reminded (from 1 to 60 minutes) and how long each break lasts (from 20 seconds to 5 minutes). The 20-20-20 rule timer starts at 20 minutes and 20 seconds, so you only need to change these if you want a longer screen break reminder, for example a 5-minute break every hour.

You can also switch the chime, desktop notifications and stretch prompts on or off independently. The tab title shows the countdown, so you can glance at it without switching tabs, and a counter shows how many breaks you have completed this session. The interval and break length are locked while the timer runs, so pause it to change them.

Why is it so hard to remember eye breaks?

Focused screen work makes time disappear. Most people intend to look away but don't notice that an hour has passed. A reminder that interrupts you at a set interval does the remembering for you.

The chime works as long as the tab is open and your sound is on. Desktop notifications only work if your browser and operating system allow them, so if they aren't showing, check site permissions and any "do not disturb" or focus mode settings.

What else reduces digital eye strain?

The 20-20-20 rule works best alongside a good setup. Practical steps recommended by eye care and workplace health bodies include:

• Screen position. Put the screen about an arm's length away with the top at or slightly below eye level. Use the monitor height calculator to work out the numbers.
• Glare control. Position screens so windows and overhead lights don't reflect on them, and adjust brightness to match the room.
• Blinking. Focusing for long periods without blinking can leave eyes dry and tired, so the AOA suggests blinking frequently during computer use.
• Text size. Increase it instead of leaning toward the screen.
• Up-to-date glasses. Uncorrected or outdated prescriptions are a common cause of eye discomfort at screens. Tell your eye care professional how much screen work you do.

For a fuller list, read our guide to remedies for eye strain.

Should I take longer screen breaks too?

Yes. Short eye breaks don't replace changes of activity. HSE guidance for display screen work calls for breaks or changes of activity, and advises short breaks often rather than longer ones less often.

Use some of your breaks to stand, walk and stretch. The optional stretch prompts are a simple start, and our desk stretches guide has more ideas you can do without leaving your workspace.

How do I make the habit stick?

Start the 20-20-20 rule timer at the beginning of your working session, the same way you open your email. For the first week, take every break even when you feel fine; the point is to rest your eyes before they get tired.

If a reminder lands mid-sentence or during a call, finish the thought and then look away. Skipping one break is fine. Skipping them all day defeats the purpose.

Who is this timer for?

Anyone who spends long stretches at a screen: office and remote workers, students, developers, designers and gamers. Safety and HR teams can also share it as a simple, free part of a display screen or workstation ergonomic assessment program.

This tool offers general wellbeing reminders, not medical advice. If eye discomfort, headaches or vision changes persist, see an optometrist or ophthalmologist.