Cross-eyed question (for the after lunch bunch)

I know we’ve discussed post-lunch nutritional narcosis, but it seems lost to the bytes of time.

OK, so we know that certain dietary combinations are bad for the afternoon consciousness. I go there from time to time (I’m slowly learning) and thus sometimes have that 2:15 PM experience of gripping the desk with both hands and looking up as the District Manager enters my office and thinking, “Man, I know I know that guy from somewhere.”

What I’m curious about is why do my eyes cross when I’m deep in the throes of this phenomenon? That’s not what happens when I get tired at night and go to sleep, but when I’m fighting the big crawfish etoufee battle in the afternoon, my binocular vision goes independent and two competeing eyes source the tired brain. It makes it very hard to contour maps.

Well, what’s happening here? Why is the dominant expression of serotonin breaching the ramparts found in my eyes crossing?