If you have ever participated in a sport or activity that involves aim, like archery, target shooting, or even darts, you have no doubt heard about and been affected by the issue of eye dominance. You may have wondered, however, exactly what that term means or what effect it might have on your vision. At Georgia Eye Physicians and Surgeons, our team of eye care specialists is fundamentally concerned with educating patients about every aspect of their eye health, and so here are the important facts that you need to know about eye dominance.
Because we have two eyes that are separated horizontally, the brain is always presented with two slightly different views of the outside world. The brain measures these differences, called binocular disparity, to calculate depth in the visual scene, giving us the perception of depth. Binocular vision is useful because it helps us perform skills such as catching and grasping, and allows humans to walk over and around obstacles, judge distances for jumping and climbing, and generally move through the environment with more assurance. However, the perceived position of an object can differ depending on the position of the observer, a phenomenon known as parallax error, and so when it is important to know exactly where an object is in space, the brain must prioritize the visual data coming from one eye over the other. The eye that the brain tends to naturally prefer is considered the “dominant eye.”
Approximately two-thirds of the population is right-eye dominant and one-third left-eye dominant, but this appears to be largely a matter of “habit,” as dominance does appear to change depending on the direction of the gaze and a small portion of the population seems to favor both eyes equally. Cases where the difference in dominance is extremely profound are sometimes caused by disorders that affect the eye movement, such as amblyopia, otherwise known as “lazy eye,” or strabismus, a misalignment of the eyes that most commonly occurs during early childhood.
Although it can be helpful to know, particularly if you are involved in aiming something, our brain’s choice of dominant eye really has no noticeable effect on your vision. While it may seem obvious that the brain would naturally favor the better-sighted eye, this is not necessarily the case. In patients with different amounts of nearsightedness between their two eyes, the dominant eye has typically been found to be the one with more myopia. Though some have suggested that cross-dominance (where the dominant eye is on one side and the dominant hand is on the other) is advantageous in sports requiring side-on stances, like baseball or golf, studies have shown that this is not true either. In cases where the dominant eye is damaged by accident or disease, the brain naturally adapts and, after a short period of adjustment, the balance and vision return to normal.
If you would like to learn more about your vision, or have concerns about your eye health, please feel free to call and schedule an appointment for a comprehensive vision exam from Dr. William Segal or Dr. Marc Lay at Georgia Eye Physicians and Surgeons. Don’t forget to follow us on Facebook, Twitter, and Google+ to get more tips for healthy eyes.