tines parent
It's quite funny, for myself, if I concentrate I can so strongly visualize something that I stop seeing through my physical eyes and kind of go "blind," only perceiving with my eyes once I decide to again or once some large visual stimulus surprises me.
Same for me. It has led to some awkward moments in public where it looks like I'm staring at someone from across the room, but I'm just thinking/visualizing and am only vaguely aware of what my eyes are looking at.