Just finished a blink reminder app https://blinktracker.app a couple of days ago. Monitors your eyes' blink frequency with a camera and also reminds you to take regular screen breaks.

Somewhat ironically after giving up smoking I take too few breaks and get blurry/dry eyes after long days. The app is a bit overengineered and comes with an api in case you ever wanted to start controlling stuff with blinks. Currently Windows only.