I was using Take a Break, which is a great minimalist product, but the behavior never took. So far, with this one, I'm actually getting up, and its persistence helps, since it can be deferred for 5 minutes if you set it, rather than being dismissed until the next period. Also, I prefer to be prompted during work, but not so much during personal time, so after turning it off, it will restart the process on the next day.

It’s such a good and simple app that I decided to buy the pro version after a couple of weeks of use. The free version has everything you need, but I wanted to support the developer for the great work. It also doubles as a very effective pomodoro timer, and the fatigue graph is a useful addition.

Basically for me it’s either this or the venerable Time Out. This is more intelligent in its monitoring AFACT but it lacks one critical, small feature that Timeout has, which is a keyboard shortcut to skip the current enforced break. For instance, if you’re in a game or meeting and a break occurs, you have to scramble for your mouse/trackpad, find the “Skip” and click it. With Timeout, you just hit a keyboard shortcut which you know off by heart. Other than that, this is the classier, better app IMO but it’s close.

And annoying. Eye Monitoring works exactly as avertised--it forces you to take a break.I have several eye problems and work far too many hours on my Mac.It's worth it. Try it, you'll like it.