Why

Your eye's deserve a break...

A small muscle in each eye stays tensed to hold focus at screen distance, and while you concentrate you blink far less than usual. A few minutes of that is fine. Hours of it is why you end the day with eye strain, dry eyes, blurry vision and headaches. The fix is simple. Look at something far away every so often, and blink. That is all the 20-20-20 rule is, and optometrists have recommended it for years.

20 MINUTES
How often. Strain builds gradually, so short resets before fatigue sets in beat one long rest after it has.
20 FEET
How far. At about six metres, the focusing muscle relaxes to its resting state. It's the visual equivalent of putting a heavy bag down.
20 SECONDS
How long. Roughly the time the muscle needs to fully let go, and enough normal blinking to re-wet your eyes.

The hard part isn't knowing the rule. It's remembering it every 20 minutes. EyeBreak is a tiny app that does the remembering. A black screen fades in over your work, an eye keeps you company for 20 seconds, and everything fades back exactly as it was.

Install

Download it, run it, done

↓ Download EyeBreak.exe

Run it once. It adds itself to Startup so it's there every time you sign in, and sits in the tray by the clock. Hover the icon for the time until your next break, or right-click it for the menu.

Windows may show a SmartScreen warning the first time, as the exe isn't signed. Choose More info, then Run anyway.

Trouble downloading the exe? Some browsers, antivirus tools and work laptops block unsigned executables outright. In that case run the source script instead — it's the same app, just not compiled:

Install AutoIt v3 — unzip it and run the setup.
Download EyeBreak2020.au3 (right-click → Save link as… if it opens in the browser).
Double-click the .au3 file to run it, or right-click → Compile Script (x64) to build your own EyeBreak.exe.

Running the script directly works exactly the same, except it won't add itself to Startup — for that, either compile it or put a shortcut to the .au3 in your Startup folder (Win+R, then shell:startup).

Settings

Customize your break

Everything lives in Documents\EyeBreak.ini. Open it from the tray menu, change what you like, then choose Reload settings.

[Timing]

WorkMinutes=20

Minutes of active screen time between breaks.

FadeSeconds=5

How long the black screen takes to fade in before the break.

BreakSeconds=20

Length of the break. 20 is the recommended minimum — longer never hurts.

BlinkEverySeconds=10

How often the eye blinks during the break.

SnoozeMinutes=5

How far a break is postponed when you press S during the fade.

DeferMinutes=2

How long to wait before retrying a break that was blocked by a call.

IdleResetMinutes=3

After this much time with no input — and nothing playing or full-screen — you're counted as away and the timer restarts. 0 turns away detection off.

[Behaviour]

PauseMedia=1

Pause whatever's playing when a break starts and resume it after. Works with anything that responds to media keys — YouTube, Spotify, VLC, most browsers.

SkipWhenMicInUse=1

If any app has the microphone open (Teams, Zoom, a recording), the break is deferred rather than blanking your screen mid-call.

BreakDuringFullScreen=1

Full-screen apps count as active watching, so breaks still fire over full-screen video and games. 0 = a silent full-screen window counts as away.

AllMonitors=1

The black overlay covers every display. 0 = primary monitor only.

ShowCountdown=1

Show the seconds number under the eye. 0 = just the eye.

AutoStart=1

Keep a copy in your Startup folder so EyeBreak runs at sign-in. 0 removes it on the next reload.

[Text]

BreakMessage

The line shown above the eye during the break.

FadeMessage

The line shown while the screen fades in.

During a break

What happens, and what you can press

Esc
Skips the break. The next one arrives in a full 20 minutes.
S during the fade
Snoozes — the break comes back in 5 minutes instead.
On a call
Nothing appears. The break waits until your mic is free.
Away, locked, asleep
Doesn't count toward a break — only active screen time does. You get a fresh 20 minutes when you're back.

Disclaimer

20s - a good start

Some science papers suggest 20s if not enough for the eye muscles to fully reset, and that the time required is 90s (1-2mins), additionally walking around instead of looking out into the distance helps reset posture.
However the key is consistancy. If you can - set your BreakSeconds=90 and change your BreakMessage=Go for a Walk!