Tonight Mr. T&A was trying to figure out which of his eyes is dominant so as to improve his skills at trap shooting,* as follows: you point your finger at a distant object, then close one eye at a time. Your finger is supposed to keep pointing at the object when one of your eyes is closed, and presto, the open one is the dominant one.
I tried it too, not wanting to neglect my trap shooting game. I pointed at a sign outside the window, but which of the two images of my finger was I supposed to be focusing on? So I asked Mr. T&A, "Which finger are you pointing with?"
So, it turns out Mr. T&A does not see two images of his finger when he points at something far away. A marathon of Googling ensued, and for about 15 minutes I thought (1) I have had double vision my entire life and never realized it, (2) maybe that concussion in second grade was worse than I thought, and (3) probably this is why I'm bad at sports.
However, the tide turned when I found this, explaining that "We all (those of us with 2 healthy eyes) have a type of diplopia called physiologic diplopia. To demonstrate this phenomenon, hold a pencil vertically about 6 inches from your face and look directly at it. Then, hold your thumb out directly behind it at arm’s length. As you maintain focus on the pencil, you will see two thumbs. This is normal." Normal! That's me! But when Mr. T&A tried it, focusing on the pencil gave him a headache. Now I think (1) Mr. T&A's eyesight is even worse than he thought, (2) my brain is fine. Fine!, and (3) yet again there is no excuse for how bad I am at sports.
But just to check, can you confirm for me that I am not the one with the crazy eyes? When you point your finger at something far away and focus on the far-away thing, do you see two of your finger, or just one?
*Trap shooting is fun! You can do it at the PG County Trap & Skeet Center. You get to yell "Pull!" and a clay pigeon flies out of this machine, and you shoot it with a shotgun. No pigeons were harmed in the creation of this blog post.