Dominant Eye Test

An eye dominance test can tell you which of your eyes is dominant. Your dominant eye is the one that sends slightly more information to your brain. It also tends to be the one you use automatically when looking into a microscope, telescope, or sight.

Also known as ocular dominance, eye dominance can be determined using a self-administered home. This information can be helpful when playing sports, taking photos, and aiming at a target.

This article describes how to test your eye dominance. It also explains why eye dominance matters and when it is useful to know which eye is dominant.

How to Test for Eye Dominance 

Eye dominance can be tested at home using different techniques. Eye dominance tests may also be administered by an eye doctor or as part of a physical for certain careers or the military.

One common test used is known as the Miles Test. This self-administered test can help you identify your dominant eye. Here's how to do it:

1. Extend your arms in front of you with your palms facing away.
2. Bring your hands together, forming a small hole by crossing the thumbs and forefingers.
3. Choose a small object about 15 to 20 feet away from you. With both eyes open, focus on the object as you look through the small hole.
4. Close one eye and then the other. When you close one eye, the object will be stationary. When you close the other eye, the object should disappear from the hole or jump to one side.
5. If the object does not move when you cover one eye, then that eye is dominant. The eye that sees the object and does not move is the dominant eye.

Other eye dominance tests include:

• The Porta test: Extend one arm in front of you. With both eyes open, align your thumb or index finger with a distant object. Alternate closing one eye to determine which eye is viewing the object. That is your dominant eye. 
• The Dolman test: This test uses a card with a hole in it. Hold the card in both hands and look at an object in the distance. Then alternate closing both eyes. The eye that sees the object is the dominant eye. 
• The convergence near-point test: In this test, focus both eyes on an object that is about arm's length away. The object is brought closer until only one eye is able to focus on it. That is your dominant eye.
  

Why Eye Dominance Matters

Eye dominance has no particular medical significance, and it may make no difference in your life. For most tasks, it doesn't matter which eye is dominant. Most people instinctively use their dominant eye for things like:

• Using a microscope
• Looking through a telescope
• Performing other tasks that involve closing one eye

Knowing which eye is dominant is helpful in careers, sports, and hobbies that require accurate aim. Examples include:

• Archery, hunting, and marksmanship: Knowing which eye is dominant may help you with your accuracy. If you try aiming with your non-dominant eye, your target won't be in the right place. Shoot with the hand that matches your dominant eye. For example, if you have a dominant left eye, you should shoot with your left hand, and vice-versa.
• Baseball and golf: These sports require good aim. Your accuracy depends on using your dominant eye when hitting the ball.
• Photography: If you aren't using your dominant eye to look through your camera's viewfinder, you may see certain details that will end up outside of the frame in the final image. Looking through your camera's viewfinder with your dominant eye ensures that the image you see is the one that you'll capture.
  

Eye dominance is also an important factor to consider with monovision contact lenses. Monovision uses two different contact lens strengths in each eye—one to see distances and the other to see up close. This reduces the need for reading glasses or bifocals.

Dominant Hand, Dominant Eye Connection

In general, eye dominance goes along with handedness. In other words, lefties' left eyes are more likely to be dominant, while righties' right eyes are likely to be dominant. But there are exceptions to this rule.

Research shows 70% to 90% of people have the same dominant hand as eye, while 10% to 30% have cross-dominant hands and eyes. Between 85% and 90% of the population are right-handed. This means the right eye is most commonly dominant.

However, cross-dominance is more common among high-level and professional athletes, including:

• 53% of soccer players
• 52.5% of golfers
• 51% of those playing team sports
• 42% of tennis players

At the same time, in sports such as archery and target shooting that require aim, 82% of higher-performing athletes have matching dominant hands and eyes.

Is It Possible to Not Have a Dominant Eye?

Most people have a dominant eye, just as most people have a dominant hand. It is rare for a person to have balanced eyes, meaning neither one is dominant. That means the person can use either eye when performing tasks in which most people use the dominant one.

It is much more common, though, to have a variation in how dominant your dominant eye is. For example, some people may have one eye that is only slightly more dominant than the other. Others may have one eye that is much more dominant than the other.

It is also possible to have mixed ocular dominance, which means one eye may be more dominant for certain tasks while the other is preferred for other tasks. 

Summary

Your dominant eye is the one that sends the most information to your brain. Some people have one eye that is much more dominant than the other, while others have an eye that is only slightly more dominant. You can find out which of your eyes is the dominant one using a simple at-home test.

Ultimately, it doesn't matter which eye is dominant, but for certain sports and professions, you may want to find out which eye you naturally favor. Using your dominant eye to aim or look through a viewfinder can improve your accuracy.