Speaker imaging

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.

Sound from each speaker travels to both ears with different delays creating depth of image. There are headphones that have feed-thru from one side to another while some headphone amplifiers simulate that.

Is it possible that sound from, for instance, right speaker to left ear is partially blocked/reflected by the left lens of the glasses?

Yes. Good point!

Best,
Roy