Core Features
1. 20-20-20 rule setup
Use the "Use 20-20-20 rule" preset button in Settings to instantly configure a 20 minute work interval and a 20 second break - the classic, most-recommended eye care schedule.
2. Customizable durations
Don't want exactly 20/20? The Settings page lets you set:
- Work interval in minutes - decimals supported, e.g.
12.5for 12 minutes 30 seconds - Break length in seconds - any value, minimum
0.1minutes (6 seconds)
3. Runs in the background from startup
Sight runs via a persistent service worker and Chrome's alarm system, so it keeps working regardless of which tab or window is active - you don't need to keep a Sight tab open.
Known limitation
This still requires Chrome itself to be running. See Known Limitations for the full explanation and workarounds.
4. Break instructions
The break tab always shows the 20-20-20 guidance:
- Look at something 20 feet away
- Keep your gaze there for the countdown
- Blink a few times to re-wet your eyes
- Relax your shoulders and take a slow breath
5. Flexible alerts
Every alert channel can be toggled independently:
| Alert | Description |
|---|---|
| Full-page break tab | Can be disabled entirely if you only want notifications or sound |
| Desktop notification | Can be disabled if you only want the tab and/or sound |
| Custom notification message | Supports the {seconds} placeholder to insert the break duration dynamically |
| Sound | Choice of chime, bell, or none |
| Toolbar icon flash | Flashes for ~20 seconds when a break starts |
| Test button | Preview your current notification settings without waiting for a real break |
6. One-click enable/disable
A single toggle switch in the popup header turns Sight on or off instantly.
7. Icon flash for ~20 seconds
When a break starts, the break tab messages the background service worker to swap the toolbar icon between its normal and alert state on a 500ms interval - a subtle, glanceable cue even if you're not looking at the break tab.
8. Countdown display
The popup shows a live MM:SS countdown to your next break (or the remaining break time if you're mid-break). It doubles as a standalone countdown timer, and includes a Reset timer button to restart the interval at any point.
9. Export / Import settings
Back up your entire configuration as a JSON file, and import it again on another device or browser install - handy when reinstalling or moving to a new machine.
10. Auto-resume after disabling
When you disable Sight from the popup, Settings lets you configure auto re-enable after N minutes (0 means it stays off indefinitely). An alarm re-enables Sight automatically once that time passes.