You’ve probably heard of people being left or right handed. Did you know that most people are also either left or right "eyed?” Being left or right-eyed doesn’t affect which hand has better handwriting or how you hold a baseball bat, though.
"Eyedness” (also called ocular or eye dominance) means that one of your eyes is "THE BOSS.” In other words, Eye dominance happens when your brain prefers the information from one eye more than the information from the other. Is one of your eyes "THE BOSS?” This experiment will help you find out.
You’ll need: paper, scissors
Make a small hole (one inch or less in diameter—one inch wide) in the middle of a piece of paper. You can download a template if you like by clicking here, and cutting out the circle in the middle. You will be looking at something across a room through the hole in the paper.
Choose something stationary (not moving) to look at across a room (at least twenty feet away) like a clock, or something on a shelf. Hold the paper with both hands, one hand on either side. Hold the paper straight in front of you at eye level with your arms fully extended.
Move the paper until you can see the object you picked through the hole. Once you can see the object through the hole, hold your head and the paper very still. Without moving your head or the paper, slowly close your left eye (keeping your right eye open) and then open your left eye and close your right. Remember to not move your head or the paper!
Most likely, when you close one of your eyes, you’ll still be able to see the object through the hole, but when you close the other eye, you will no longer be able the object. The eye that can still see the object when the other is closed is your dominant eye (THE BOSS.)
Here are some pictures of Ethan P. trying this experiment.
Ethan P. holding the paper at eye level, extending arms straight in front, and looking through the hole
The clock Ethan is looking at across the room. What Ethan sees as he looks through the hole at the clock.
How does it work?
Your left and right eyes see things from slightly different angles, and usually your brain uses the slight differences to help you figure out how close or far away things are (optometrists call this depth perception, or stereo acuity.) When you look at something very close to you, the information from your two eyes is quite a bit different than when you look at something far away, and your brain has to decide which eye it should believe when it is trying to figure out exactly where something is.
You can try this, too. Hold your finger directly in front of your left eye, about three inches away from your face. Holding your head and finger still, first close your left eye, and then your right. Your two eyes are reporting different things to your brain, right? Your brain tends to pick one eye to be in charge of determining the exact spatial location of things when your eyes are telling it different things. This eye becomes your dominant eye, or "THE BOSS.”
Other Interesting Facts
- Some people have very mild eye dominance (one eye is just a little bossy) while others have extreme eye dominance (one eye is VERY bossy.)
- According to several scientific studies, it seems more people (about two-thirds of the people in the studies) are right eye dominant and only about one third are left-eye dominant.
- Determining eye dominance is important for some kinds of contact lenses and eye surgeries
If you like this experiment and want to explore more about your senses or optical phenomena, you might like these two kits from Be Amazing:
Come to Your Senses