Info screen

Bagher_mo68

Hi all,

Today after a long time working with my D5100, I started shooting and found something strange!
Normally when I put the visor in front of my eye the Info screen went off, but as of today it doesn't goes off automatically!
So, I searched in the menu for this, and I just found an option for how long info screen stays on, and if it goes on and off automatically (when we press the shutter button and release it) or not! Nothing about turning it off when we put the camera in front of our face!
Is it possible that there is a problem with my camera's back sensor (the camera can't find out if we put our camera in front of our face) or is this an optional feature that I don't know where to find?