BRIGHTNESS LEVEL FIXED ON SONY VAIO VPCEH38FN

[Atish Pandey]

Hello everyone,
I am new to Debian, and have recently installed Debian 8.6 Jessie GNOME 3.0 on 
my sony vaio VPCEH38FN. It has a Nvidia Geforce 410 M graphics card.
The issue is that the screen brightness is set to maximum and it is not 
changing by hotkeys Fn+F6/F5.The brightness indicator changes the value but it 
doesnot reflect on the screen.
Any help would be appreciate.Thanks in advanced.
Atish