I'll second the first paragraph here. The demonstration I've come up with involves holding a hand closely in front of only my left eye. My brain lets me see bot

I'll second the first paragraph here. The demonstration I've come up with involves holding a hand closely in front of only my left eye. My brain lets me see both things, but my hand also has a 'transparent' characteristic when I'm focusing on my right vision. Back to visualizing, the 'other source' isn't anywhere near as crisp as the demonstration, and often is a mix of memory / imagination / caricature / labeling it with the concept.