Break Timer is an application that announces you when you need to take a break from your computer. Once the program is enabled, your computer refuses to do anything else for you until you rest your eyes and grab some fresh air going for a walk.
You need to set the time you want to take a break. A countdown clock will warn you about the incoming break moment - then your screen will darken. When the time for your break is up, your computer lights up and you are back in control as if nothing happened.