Yesterday I was having a non lucid dream of swimming in the river. The dream was not extraordinary but the way that I woke from it was. I slowly awoke and opened one eye. The open eye saw my room and I am sure this was reality, not the dream. My closed eye remained viewing the dream for about 15-20 secs. My field of vision was vertically split between reality and a dream. The open eye was viewing my static bedroom surroundings while the dream continued to move and develop. The only way I can explain this was that one brain hemisphere remained dreaming while the other was awake. For the record, my left was the open one seeing my real surroundings. So my right brain had awoken first?