20-20-20 Eye Strain Timer

Staring at a screen for long, unbroken stretches is one of the most common causes of digital eye strain — dry eyes, blurred vision and headaches that creep in during a focused work session without you noticing until it's uncomfortable. The American Optometric Association addresses this with a simple, memorable guideline known as the 20-20-20 rule: every 20 minutes, look at something roughly 20 feet away for at least 20 seconds. Shifting focus to a distant object relaxes the eye's focusing muscles, which stay contracted and fatigued when everything you look at is an arm's length away.

The rule is easy to state and easy to forget the moment you're absorbed in a task, which is exactly the gap this timer fills. Press Start and it counts down 20 minutes in the background, visible both on the page and mirrored live into the browser tab title, so the remaining time stays in view even while you're working in a different tab. When the countdown reaches zero, the page doesn't just play a generic notification sound — it switches into a full break view with its own 20-second countdown, drawn as a shrinking circular ring, and a clear instruction to look at something roughly 20 feet (about 6 meters) away until the ring finishes.

A soft two-note chime, generated live by your browser's audio engine rather than an audio file, plays at the moment each break begins, so you notice it even if the tab isn't focused. Once the 20-second break countdown completes, the timer resets itself automatically and starts the next 20-minute cycle without you touching a button — the whole rhythm keeps running on its own for as long as you leave the tab open. A running count of completed breaks gives you a quick sense of how many cycles you've actually done in a session, and pause and reset controls are there for whenever you step away or want to start fresh.

Like every tool on this site, the 20-20-20 timer runs entirely in your browser: nothing is uploaded, nothing about your work habits is tracked, and no account or installation is needed. The one honest limitation is that the tab needs to stay open — the countdown lives in this page's memory, not in a background service, so closing the tab or refreshing the page resets the cycle. Keep it open in a spare tab next to your work and let the 20-20-20 rule take care of itself.