Friendeye is a useful application for people who work on computers late at night. It is a free, portable screen filtering application that allows users to manually adjust their screen brightness level using just their mouse, without bothering about monitor controls.
As it is a standalone app, you can start using it immediately after downloading by double-clicking on Friendeye.exe executable file. It runs from the system tray, and this is all you need to work with the app while you carry on your work.
To enable the screen filter, simply left-click on the application icon. Your screen will be instantly dimmed. To get back to the normal brightness level, click on the icon again.
To change the brightness level, right-click on the tray icon. You are immediately met with a dark overlay. At the top-left corner of the screen, you should see the brightness level controller. The higher the value you set here, the lower the brightness. For instance, if you set 80%, your screen would be almost dark with only 20% of brightness. Brightness level is shown real-time while you adjust value. This gives you a better idea of the selected brightness level.
There are other similar application like F.lux and Redshift that automatically adjusts the screen color temperature depending on time of day, but if you prefer manual control, Friendeye is a nice application to have.
Friendeye is compatible with Windows XP and newer.
Download: Friendeye