Free Monitor Manager is an uncomplicated option for adjusting your monitor(s) settings from your keyboard.

It allows you to create profiles to suit different work environments, and if you want to upgrade to the personal license (you do get 15 days to try out full functionality), you also can have specific apps with set adjustments. This is useful when you want to watch a movie and would like to have the screen brightness dimmed for instance.

Free Monitor Manager simply allows you to manage screen settings while you are working without the need to fiddle around with the actual hardware.