On my GS3 this was working fine untill yesterday, but it has now decided to keep the screen on untill i turn it off via the lock key. The screen will dim out, then the little eye will pop up and then the screen goes bright again and stays like that with the little eye popping up all the time and just keeping the screen on when I'm not even near it!. Oh and I've tried factory resetting but it's still doing it. I've been running JB 4.1.1 for a few weeks prior to this happening by the way. Any idear's guys?.