[tzs]

That 20/20/20 rule, assuming that the exact times are not critical, would fit in well for people using the Pomodoro Technique [1] for time management or something similar.

I find it interesting that it also fits will with ergonomic recommendations. Both sitting too long while doing computer work and standing too long are bad for you. See this article from the old Cornell ergonomics group site [2] for details on the perils of both. Their recommendation:

> Sit to do computer work. Sit using a height-adjustable, downward titling keyboard tray for the best work posture, then every 20 minutes stand for 8 minutes AND MOVE for 2 minutes. The absolute time isn’t critical but about every 20-30 minutes take a posture break and stand and move for a couple of minutes. Simply standing is insufficient. Movement is important to get blood circulation through the muscles. And movement is FREE! Research shows that you don’t need to do vigorous exercise (e.g. jumping jacks) to get the benefits, just walking around is sufficient. So build in a pattern of creating greater movement variety in the workplace (e.g. walk to a printer, water fountain, stand for a meeting, take the stairs, walk around the floor, park a bit further away from the building each day).

Do something like pomodoro for time management and during the breaks between pomodoros spend a couple minutes walking around and looking at things in the distance and you've covered protecting both body health and eye health from the risks of computer work.

[1] https://en.wikipedia.org/wiki/Pomodoro_Technique

[2] https://ergo.human.cornell.edu/CUESitStand.html