I also get this.
I used to have visions, but now it's just not being able to move.
Once I woke to this, only being able to move my eyes, I could see that my brother was in my room on the spare PC, I tried to make a noise, even breath harder but could not get his attention, gave up and went to sleep again ( I already knew what was happening so I didn't panic) All I could do was look around and blink.
He said he once saw me do this but I wouldnt react to anything.
It's lasted as long as 10seconds to having to fall asleep again and.. (hope) it goes away! :O