Eyes open or closed?

Depends. They're always open when I'm driving, for example.

Open, and with good imaging I can see the performers. Especially with a black background.

Closed eyes I'd be asleep in no time. 

I generally listen with my eyes closed.  @cleeds exception noted.  I like to daydream when listening to music.  OK, sometimes I nod off, but generally speaking, If I'm sitting listening to music with my eyes open, I get distracted from the music.  It's much easier to slow my mind down and get immersed in the music with my eyes closed.  

Closed.  Every time. Easier to lose the speakers and become immersed in the soundstage. Everything sounds better with eyes closed, and it costs nothing.

Eyes opened (reading) for a while before going into sleep mode...

+1 @gdaddy1 

When your system throws great images, no point is not watching them dance in front of you. That is the actual fun!

Usually, eyes opened in a lighted, or sometimes, a dimmed, but not dark room. 

For me, the image and soundstage on my system, is so well defined, closing my eyes does not help enhance the illusion at all. 

It depends.....

It depends on who I'm with and what I think they'll look like in the morning. 

Rainbow rising?

Closed WITH GLASSES OFF for the best imaging.

Lurker now posting finally. I'm an optometrist and I had a long conversation many years ago with a professor of ocular physiology.  He taught our "psychophysics of monocular and binocular vision" in Philadelphia.  He was also an audiophile.  I told him I preferred to listen to music in a pitch black room and eyes open, and he agreed that was probably preferred.  The reason being the proprioceptive ability of the brain to know EXACTLY where the eyes are pointed. It is not so easy with eyes closed to "look at something."  So his feeling, and I tend to agree, is that with eyes open in a dark room you are able to physically place the performers and instruments in a room due to the positional feedback from the eyes.  I have had this discussion with more than one engineer from McIntosh Labs (a few miles from my office) and they are engineers, they really have no opinion. So there's that.  I don't think there's a right answer.  

Eyes closed, but I might be an outlier, I don’t tune for imaging, as I don’t hear it when I go to the concert hall.

Zero class