I think it’s pretty interesting that my eyes can see without seeing.  For example, when I’m walking through the hallways at work, my eyes often end up in collision-avoidance mode.  That is, I don’t see through my eyes because I’m busy seeing something else in my mind’s eye.  So my eyes become visible-spectrum sonar and keep me from bumping into people and things.  It’s often while in this mode that friends and coworkers will go out of their way to snap me out of my trance to bring to my attention the fact that I didn’t acknowledge their presence in the hallway.  They never believe me that I didn’t see them because they were the only person in the hallway.  In extreme cases I have literally manoeuvred around a person to get into a door or otherwise not crash, and still did not see the person.  I mean, my brain knows I went around a human, but it doesn’t bother to decode the face so I have no idea who I narrowly missed.  This makes them even more incredulous when I deny having seen them.  Sorry, but it’s true.  My brain decided that whatever it was picturing was more important than dedicating some neurons for facial recognition.

Of course this is a fairly rational adaptation.  Otherwise every time you wanted to think about something you’d have to close your eyes.  Great way to be eaten by a predator.  On the other hand being able to walk around and only being snapped out of it by the sight of a predator would allow many inventions to come about. Does this happen to anyone else?