Do you listen to your music with your eyes open or closed or a combination of both?

 Closed. to my ears it enhances the whole soundstage/imaging thingy....

Both, but I prefer to keep them open while the room is as dark as I can get it. I also always remove my glasses @immatthewj I think I read about this little tweak in Listener years ago and it definitely makes a difference, at least for me. It certainly stands to reason - you are basically removing a highly reflective surface from a spot inches in front of your ears.

I listen exclusively at night, blacked out room, I do combo, mostly closed however. I want no distractions during my listening sessions, no visual stimulation for me.

Well, both, but if I keep my eyes closed for too long I fall asleep !

Both - it often depends on the music....