You can tell it has night vision from the windshield.
I have it on mine - when active, it uses the 'projector' headlights on the lower bumper to shoot out invisible IR light which is picked up by a camera mounted behind the rear view mirror. The image received by the camera is displayed on a reflective surface on the windshield directly above the dashboard. The image is black and white. The bulbs used by the system are regular $15 halogens, but there's a filter installed in the projector housing to only let the IR light pass. The system is available when it's dark, and when the headlights are on.
For me, it's actually more of a distraction to use the system than simply paying attention to the road. The system has a slight lag - so in my windy wooded, hilly country roads it's not extremely useful. The image displayed is somewhat small, and the resolution isn't great.
However, it is fun to tell people your truck has night vision.