If you're in need of a little help, EyeDefender might be the reminder you need. It's controlled almost entirely from the taskbar. You'll decide how often you want to take a break and how long the break should be - both of these are completely customizable - and then you just have to choose what happens while you're taking the break.
This is where EyeDefender really comes into its own. You can chose the most low-key option, a pop-up in the system tray, or something slightly more obvious - your default screensaver, a folder of your own photos, EyeDefender's default photo or a series of eye exercises. These exercises are very simple, but provide effective relief from the glare of the screen. You can disable the rest period with the ESC button if you need to, or just wait until the time is up. Not everybody thinks thet need an eye relaxation program, but if you do, EyeDefender is a great option.
EyeDefender - flexible, functional and fun.