Opencv face detection on IR video

i have tried it with a logitech c920 without the ir cut filter in this custom housing
http://lukse.lt/uzrasai/2013-07-modifying-logitech-c920-to-for-cs-lenses/
and an IR illuminator.

i have read that face detection looks for the white line on the bridge of your nose, where the light reflects more and the dark of your eye and some other stuff.
I am guess in an IR image these features do not look the same necessarily.