Dominant eye test: how to determine your dominant eye

You’ve probably heard the terms dominant eye and ocular dominance, but do you know what they mean or how to determine which eye is dominant? Below you will find basic information on Dominant eye test …

Dominant Eye – What is it?

The dominant eye is the one that transmits a slightly larger amount of information through itself to the visual region of the brain and more accurately conveys information about the location of objects.

In most cases, the term “dominant eye” is used to describe the ordinary vision,
when two eyes function equally well, with little difference in visual acuity,
and one eye is simply “dominant ” or preferred.

But sometimes by “dominant eye” is meant a normally functioning eye
with good vision in functional disorders of the other eye, such as amblyopia and strabismus.

Dominant eye test

To find out which eye is your dominant or preferred eye, you can perform a simple dominant eye test:

1. Stretching your arms forward and folding them together at a 45-degree angle, connect your thumbs and forefingers so that a triangle forms between them.
2. With both eyes open, focus your gaze through this triangular hole on any object in the distance, such as a wall clock or a doorknob.
3. Close your left eye.
4. If the subject remains in the center of the triangle, your right (open) eye is dominant. If the subject is outside the triangle, your left eye is dominant.

Here’s another simple dominant eye test:

1. Extend one hand while holding your thumb (or index) finger upright.
2. Without closing your eyes, focus your gaze on the distant object and place an outstretched finger on it (the finger will partially disappear from the field of view – do not worry, this is normal).
3. Close one eye at a time.
4. The eye that sees the finger closer to the center of the object
   while the other eye is closed is dominant.

The methods for determining the dominant eye described above are categorized
as “scoped” tests because they involve centering the selected object with an impromptu “sight”
(similar to the one mounted on the barrel of a rifle).

Some studies have shown that dominant eye tests, while simple to perform and generally accurate, may be influenced by hand preference (see below) and other non-visual factors.

In this regard, some researchers argue that tests without aiming are a more accurate way of determining the dominance (ocular dominance) of one of the eyes, in which the factor of right-handedness or left-handedness cannot distort the test result.

The essence of the “aimless” tests is that with the help of special optical devices,
visual stimuli are simultaneously demonstrated to each of the eyes,
which the subject keeps open throughout the test. And therein lies the limitation of unscoped tests –
the equipment and expertise required to perform them are usually only available in specialized ophthalmology clinics or vision centers.

However, in most cases, simple aiming tests like the ones described above can reliably determine your dominant eye.

The dominance of one eye and preference of one of the hands

Although the dominance of one of the eyes and the preference of one of the hands (right-handedness or left-handedness) are not directly related, there is definitely a certain relationship between these features.

Although it has been shown that a right-handed person is highly likely to have right eye dominance (this is about 2.5 times more likely than a left-handed person), it is impossible to predict for sure the preference of one of the eyes based on right-handedness or left-handedness criteria alone.

Lack of a dominant eye: Is it possible?

Is it possible not to have a dominant eye? This is possible but unlikely.

If the degree of dominance of one of the eyes is not obvious during the dominant eye test, it is most likely that the person has mixed (or alternating) ocular dominance. In this case, one eye is dominant in performing certain functions or tasks, while the other eye is dominant in other cases.

For some people, when performing a “targeting” dominant eye test, it is not possible to place the visual target exactly in the center of the triangle or directly in front of the thumb/forefinger (depending on the type of test) when using either eye.

The degree of dominance of one of the eyes in people varies greatly
(the same can be said about the preference of one of the hands). In other words, in some, the dominant eye can be very dominant, while in others, the dominance of one of the eyes is less pronounced.

To some extent, this criterion is predetermined in our brain.

The visual cortex (the area of ​​the brain responsible for processing visual information) contains bands of nerve cells (neurons) called the columns of the dominant eye. These bands of neurons appear to be predominantly responsive to visual information from one eye or the other and play an important role in the development of binocular vision.

At the same time, the researchers believe that there is some overlap and plasticity of these columns of the dominant eye, due to which the dominance of one of the eyes in some people may be variable, alternating, and, possibly, incomplete.

The dominant eye in shooters, photographers, and athletes

So what is the practical value of the dominant eye test?

Knowing which eye you have is dominant, you can better perform various actions. Here are just a few common examples:

Dominant eye when shooting. Having trouble hitting moving targets with a rifle? You may be missing the parallelism of dominance — in other words, your dominant eye and dominant hand are on opposite sides of your body.

For example, if you are a right-handed shooter (and therefore your right shoulder is preferred)
but your left eye dominates, you may find yourself shooting behind a target moving from left to right
and in front of a target moving from right to left. Knowing this will help you make the right adjustments
and improve your shooting accuracy.

Another option to compensate for cross-dominance is to keep both eyes open until the shot is fired. By leaving both eyes open, you can use your peripheral vision and depth perception 100% to prepare for the shot. For example, if a right-hander closes his left dominant eye just before a shot, he can make adjustments at the last moment to aim his scope as accurately as possible at a moving target.

Dominant eye when photographing. 

When looking through the viewfinder of a digital SLR camera (DSLR) or similar film camera, it is important to know which eye is dominant.

Using the dominant eye will create an accurate image of the future shot for you. Conversely, using a non-dominant eye will result in some detail shifting slightly to the side or out of frame.

The dominant eye in sports. If you (like most people) are right-handed and have a dominant right eye,
some sports require you to hold your head correctly.

For example, when hitting a baseball, softball, or cricket, you need to turn your head so that your dominant right eye can clearly see and judge the spin, speed, and position of the oncoming ball.

Another example is golf. To drive the ball into the hole when performing rolling strikes
(and during fairway strikes and driver strikes), such head turns are required
and the correct positioning of your body and club.

If you are serious about sports and want to learn how to use your eyes to improve athletic performance, visit an ophthalmologist who specializes in sports vision.

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