If you are using Xmonad or other different desktop envioments and using gnome-settings-daemon
$ sudo /usr/lib/gnome-settings-daemon/gsd-backlight-helper --set-brightness (0-1000 range)
change screen brightness from cmdline
If you are using Xmonad or other different desktop envioments and using gnome-settings-daemon
$ sudo /usr/lib/gnome-settings-daemon/gsd-backlight-helper --set-brightness (0-1000 range)