I am using a Samsung NP-X420 with Lubuntu 14.04. The screen is so bright that it irritates my eyes. When I press the brightness adjustment keys on the keyboard (Fn+down arrow), I can see the window that appears on the top right corner, which is showing that it is changing the brightness, but nothing happens. The bar is moving left and right but the brightness remains harsh.
Is there another way to adjust the brightness? Do I need to install drivers? If yes, then please tell me which ones. I am not so familiar with computer stuff.
Thanks in advance!
xbacklight
to control my laptop brightness,sudo apt-get install xbacklight
and for operation just type on terminalxbacklight -set 50