Visual Exercises and Training to Reduce Eye Strain
Channel: Digital Inspiration
Date: 20/07/2010

These visual exercises are designed to prevent eyestrain, blurred vision, headaches, and sore eyes resulting from working on a computer for hours.

https://www.labnol.org/software/computer-eye-exercise/14069/

The 20-20-20 rule suggests that after every 20 minutes,  the computer user should take a break for at least 20 seconds and look at objects that are 20 feet away.