I lay on my back with my laptop up on my chest and the screen about half a foot away from my head.
Sometimes, when I get really tired, I fall into this cycle where I doze off, drop the screen on my forehead, wake up enough to put it back into place, doze off, drop the screen on my forehead, wake up enough to put it back into place, ect.
Sometimes it takes me five or six times before I wake up enough to think about putting the damn thing away.
I’ve actually had this happen to me a few times. Reading in bed with my iPad and I get so tired that I start to fall asleep, naturally my hand muscles relax and THWACK! Right in the face.