What Roy Johnson said. I don't know about the psychoacoustics piece, but things definitely seem to sound better and more dimensional with my glasses off. I also suspect that -- being REALLY nearsighted -- not being able to see my rig as clearly helps me concentrate better on the sound.
Speaker imaging
Considering my speakers definitely image better when I am not wearing my glasses leads me to conclude imaging ain't really real but relies on the power of suggestion. Sort of like some folks who prefer to listen with the lights off. Any comments?