20:00
People who use computers for prolonged periods of time (whether it's for work, leisure, hobbies or all of the above) are more at risk of developing eye strain.1 Common symptoms of eye strain include sore, burning and dry eyes alongside blurred vision, headaches, sensitivity to light, difficulties with concentrating and keeping eyes open, double vision, itchy eyes and soreness in areas such as the neck, back and/or shoulders.2 Eye professionals recommend using the 20-20-20 rule when looking at screens for long periods of time - Twenty-20-20 is a tool built to help with that!
Every 20 minutes of screen-time, take a break for at least 20 seconds by looking at something at least 20 feet (or about 6 meters) away. It doesn't have to be exact measurements - the idea is to look at a distant object (that is, for example, outside and seen through a nearby window) to relax your ciliary muscles.3