Your desktop environment should already have come bundled with some button for adjusting the screen brightness. The brightness adjusts the backlight intensity that illuminates the screen. I used the one that comes by default in Gnome 3 and I felt that my display was not bright enough. I thought I’ll tinker a bit from the command line. RandR is an extension to the X display server that allows such tinkering as and when necessary. Within most Linux distributions there is a small utility called xrandr which comes handy to interface with RandR.

Let’s find out the connected screens:

ish@inote:~> xrandr -q | grep connected
LVDS1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 309mm x 173mm
DP1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
VGA1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

As we note from the output LVDS1 is the only connected screen. To adjust its brightness we’ll shoot:

ish@inote:~> xrandr –output LVDS1 –brightness 0.8

1.0 being the max while 0.0 is a blackout. If you go above 1.0 display becomes weird.