What is the 20-20-20 rule?
The 20-20-20 rule is a simple guideline for reducing digital eye strain: every 20 minutes of screen time, look at something at least 20 feet away for 20 seconds. It was popularised by optometrist Dr. Jeff Anshel and is now widely recommended by eye care professionals.
Does the 20-20-20 rule actually work?
Research suggests it helps. A 2023 study found that participants who followed the rule reported significantly less eye fatigue after prolonged computer use. The mechanism is straightforward — looking at a distant object relaxes the ciliary muscles in your eye that stay contracted when focusing on a nearby screen.
Why blink rate matters too
The 20-20-20 rule addresses muscle fatigue but not the other major cause of digital eye strain: reduced blinking. Studies show that people blink up to 66% less when staring at a screen. Each blink coats your eye in a fresh tear film — without it, your eyes dry out and irritate faster. The 20-20-20 rule alone won't fix that.
That's what blink! tracks. It monitors your actual blink rate in real time and tells you when it drops — not on a fixed schedule, but when your eyes actually need it.