CareUEyes - CareUEyes is an eye protection software for windows that comes with blue light filter, screen dimmer, and break reminder
Monitor Bright - Monitor Bright reduces with a simple trick the monitor brightness.
Simple Screen Shade - Description and screenshots of Simple Screen Shade.
PangoBright - Screen dimming software that allows you to control the brightness of your laptop screens as well as external monitors.
Nocturne - Nocturne is simple app for switching a computer to night vision mode.
LG OnScreen Control - Allows to set the brightness (and other settings) of the monitor through DDC/CI. Meaning: keyboard and/mouse instead of having to fiddle with the OSD menu manually. http://www.lg.com/us/support/monitors