Dim Everything On Desktop Except your Focused Window using Le Dimmer: Some people prefer High contrast and Brightness when they work, Some people don’t like these settings.
Le Dimmer is very useful tiny app designed for low lighting intensity. It has no user interface and settings. It is download as a zip file when you extract it a simple folder appears. It doesn’t need and installation just open the program to work.
If you want to stop the dimming simply quit the program just right clicking on the icon in the context menu. It works on Windows XP, Windows Vista, Windows 7 and Windows 8 both for 32-bit and 64-bit.