PPRuNe Forums - Metal protruding thing on top of the glareshield (B737)

Hi to you all,
I'm new around here and this is my first post. I'm a newbie 737 F.O.
I know this might be a lame question for most people around here, but I've been asking around and no one gave me a convincing answer .
I was wondering what the little metal thingy over the glareshield was for. I cannot post photos because I'm new, but I guess you know what I'm referring to. It's a little metal piece right between the windshield and the aft edge of the glareshield
Some told me it was some sort of fixation point to place the flashlight (like for looking for ice during the night) in former 737 models. I am not quite convinced. The flashlight mount doesn't seem to ever have had a shape that would fit there and I would be surprised if they had it reshaped and (at the same time) let that metal thing stay up there.
Others told me it has something to do with the light detectors (in my opinion, totally discarded because we know the light detectors for the instruments are mounted on the frames). None the less, if you scrape the forward face of the thing with your nail, you will notice a little hole (which would only be seen from the other side of the windshield). So... Still more intriguing.
So, I was wondering if you could shed some light on this issue.
Thanks in advance,
Pablo.