I know many of y’all are familiar with the old eat-lunch-commence-desparate-struggle-to-stay-awake routine. Gets me several days a week. One aspect of the whole experience I don’t understand. What is it that makes my eyes start to cross when the sleepiness wells up?
Just a WAG–it’s muscle fatigue, of the muscles that serve to focus your eyes.
Or are you talking about the 3 p.m. office doldrums? Ah, then it’s not simple muscle fatigue–it’s an evil spell put on you by the co-worker with the big butt… Look around. See her? That’s her, she’s the one. 
[I thought George, Paul, or Ringo must have died]
[because you would hardly have posted a thread that you had died]
[and you would hardly have posted a “good night all” thread in GQ]
[unless you were really really tired]
[so I figured somebody had died in his sleep]
[glad to see I was wrong]
Ducky, not a bad WAG (and I did think twice about the thread title, but thought ahh…, what the heck), but if I skip lunch I miss the nutritional narcosis experience as well as, or including, the crossing of eyes. Presumably my eye muscles that have been directing the orbs in their perusals of maps and seismic data are similarly fatigued after a morning of that whether I have lunch or not. I think. So I suspect there is some part of the post lunch metabolic swat down that causes the effect.
beatle, I b’lieve you have to include the Texas Factor. Your poor ol’ eye boggles are so overwhelmed with taking in the immenseness of it all, that whenever they have the perchance of bailing via whatever fine gastric burrito invective offered, they just shimmy wobble and do. Mebbe ya need to take a vacance into the twists of Big Bend and refocus. Sounds like a serious condition to me.
I was born with crossed eyes. It’s rarely noticeable, but when I’m very tired, it takes conscious effort to keep them properly synchronized.
I take it as another effect of sleepiness.
Man, I can’t answer the question but I’ll commiserate. Whenever I’m in any kind of meeting or other situation where I’m not actively doing anything, just sitting and listening to someone…ugh, I’m out like a light.
As your mind spirals off to sleep, it disassociates with your senses and goes internal, filling you hearing and vision with the calls and eclectic visions of half-dreams. Same thing happens to your balance, I can’t tell you how many times I’ve tripped over a rock in my mind while skipping down some golden pathway and, through struggling to keep myself balanced, lurched myself back into consiousness to the amusement of my co-workers.
Your eyes cross because you brain stops needing them and they start to do their own thing and rest.
beatle, what are you eating (and drinking) for lunch on the days when this happens? It sounds to me like what you’re experiencing is drowsiness after eating. There are some foods that can increase drowsiness at least a little, and I imagine you’re especially susceptible to that during the early afternoon, when lots of people hit a low point in their circadian rythym. Also, size of meal can make a difference - how much are you eating?
The eye crossing thing is, of course, a function of being drowsy and trying to stay awake.
Yeah, the diet’s not the point here. The eye-crossing thing being a function of being drowsy is. AFAICT Mirage’s answer makes the most sense so far.