Blind man shocks researchers with what he sees.
Here's my story:  Three (or was it four?) day non-stop coding stint to get a robot ready for a conference.  No sleep at all.  Almost non-stop coding and the usual coffee+sugar+pizza binge.  Got on a plane to go to the conference and continued coding in flight.  Got to the hotel, checked in and decided to get some sleep.  I woke up about three or four hours later.  I started to hear a nearly perfect 1KHz tone as my field of view slowly (30 sec?) faded to full bright white.  By this time I was sitting on the bathroom floor:  I could only hear this tone and all I saw was a bright white light.  Somehow I kept my cool and could, also somehow, navigate the room.  Over the following few minutes the tone started to go away and my field of view returned to normal.  Freaked the crap out of me.  No permanent damage that I could identify.  Now I keep my overnighters to just one night, only if there's absolutely not choice at all.