I mentioned in my previous post in passing about determining which was my “dominant eye,” something I’ve merrily gone 22 years without knowing I had.

Wikipedia refers to the subject as ocular dominance. Essentially, the brain “prefers” one eye over the other. Of course, this is something that ordinarily goes unnoticed, but it becomes quite important in some things, including, apparently, firing a weapon. There are two easy tests to determine your “eyedness,” as Wikipedia strangely lists as an accepted name:

• Focus on a distant (6-10 feet is plenty) object. Hold both arms out in front of you, overlapping, and form a golf-ball-sized circle between your thumbs, viewing the image through it. And then, do one of the following:
  • Slowly pull your hands towards your face, keeping the image centered in the hole. Eventually, your hands end up in front of one eye. That’s your dominant eye.
  • Rather than pulling your hands back towards you and looking ridiculous, close one at a time. With one eye, you won’t be able to see the object: your hand covers it. (If you can see it through both, the hole through which you’re viewing it is way too big.) The eye you can see the object through is your dominant eye.
• Or, with both eyes open and without paying too much attention, point at a distant object. (Don’t look at your finger or you’ll screw things up and have to start over.) Hold your arm steady and close one eye at a time. One finger will be pointing (more or less) right at the thing. The other is pretty far off. The one that’s accurate is your dominant eye.

Of course, I’m left wondering a few things:

• Can you accurately use your non-dominant eye? With one eye closed, if you can align the sights of a gun with your target, isn’t it still going to be accurate? I’m trying to ‘test’ this, but doing it with a flashlight isn’t accurate enough, and I don’t have a laser pointer. Further, I feel like a total goofball sitting here squinting with one eye and shining a flashlight at the electrical socket on the other side of the room. To align the flashlight and flashlight, I do shift the flashlight a little, but in both cases, it’s being pointed in the same place; it’s just a question of the angle.
• Can you change your dominant eye through practice or the like?
• What are the implications in daily life of having your dominant eye be your weaker eye? Uncorrected, I’m something like 20/300 in that eye. Would my perception of scenes be better if my dominant eye was the one with better vision?
• The Wikipedia page makes a cursory mention of the two eyes and how they’re processed by the two brain hemispheres. Does this related to being right-brained or left-brained? Is this like the spinning girl and seeing whether she spins right or left?