Sleeping with one eye open

I put Owen down for his morning nap today and he woke up an hour later to eat.  After i fed him he fell asleep on my shoulder. We were in the living room and so i slid down to the floor and moved him over on to a blanket to finish his nap.  Well he seriously had one eye open, so every time i tried to get up and go do something he woke up. I had to lie next to him till both eyes were closed. it was so funny.