What Is Eye Dominance and Why Is It Important?

What Are the Different Types of Eye Dominance?

There are three types of eye dominance, and they each kick in at different times and for different reasons.

Acuity dominance

Acuity is how clearly you see at a distance. Normal acuity is called 20-20 vision. But if you don’t have 20-20 vision, your eye with better acuity may take the lead, depending on the situation.

Motor (sighting) dominance

When you look at something, one eye works harder to bring the image into focus. This is called motor or sighting dominance. When people talk about eye dominance, they’re usually talking about this specific type of eye dominance.

Sensory dominance

When your eyes take in competing information, your brain weighs the info from one eye over the other. Your brain relies on the eye that shows the clearer image.

Why Your Dominant Eye Is Important

Knowing which eye is dominant can be important for activities that require you to focus on a target. These activities include:

• Baseball
• Cricket
• Golf
• Shooting
• Using a telescope
• Using a microscope

Many people don’t realize they have a dominant eye until they’re given an eye exam to test which eye functions better. If you’re cross-dominant, you’ll likely need to make adjustments when playing sports such as golf or baseball.

How to Find Out Which Eye Is Your Dominant Eye

If you’re not sure which eye is your dominant eye, doctors can do some tests to find out.

Tests to find out which is your dominant eye

Ophthalmology and optometry clinics have equipment designed to test your eyes and will be able to give you the best results. Eye doctors commonly use the “+1.50D blur” test to check for eye dominance. This test uses a series of lenses. An eye doctor will change the lenses and ask you what you see.

How to check your dominant eye at home

If you want to try to figure out which eye is your dominant eye without a visit to the doctor, there are several easy tests you can do yourself. These “home” tests are surprisingly accurate:

• Hole in the card test
• Point test
• Thumb test

The “hole in the card” test is the most commonly used test for finding your dominant eye. It uses a rectangular card with a small hole in it. 

You can do the test yourself by cutting a quarter-sized hole in an index card. Hold the card at arm’s length in front of you with both hands and use both eyes to focus on an object several feet away. Keeping both eyes open, move the card until you see the item in the center of the hole. Slowly bring the card toward you, keeping the object in the center of your vision, until it touches your face. The eye that the hole ends up in front of is your dominant eye. 

In a similar way, you can also: 

1. Make a circle with your hand and fully stretch out your arm.
2. Look through that circle at a distant object. 
3. As you look at the object, close one eye. Notice where the object is.
4. Now, switch gears and close the other eye. When you’re using your dominant eye, the object will stay in the center.

Does Eye Dominance Affect Vision Health?

Your eye doctor may need to check which eye is dominant to make decisions about your eye health and treatment plans.

When your eyes have trouble focusing on nearby objects, such as your smartphone or a restaurant menu, a doctor may recommend monovision. That’s a corrective technique that improves your near vision while still letting you clearly see faraway things. It includes: 

• Artificial intraocular lenses (IOLs)
• Corrective eye surgery
• Glasses
• Contact lenses

Depending on your situation, an eye doctor may prescribe one of these to correct the vision in your dominant eye but leave your nondominant eye alone. Both eyes will work together so you can see clearly.

If you use monovision contact lenses, you need to know which eye you use for each type of vision so you can put the correct contact in each eye. One contact will be for near vision, and the other will be for distance vision. The contact for distance will likely be placed in your dominant eye.

Other vision conditions that may need a dominant eye assessment include:

• Amblyopia (“lazy eye”).The vision in one eye is much weaker than the other. 
• Crossed eyes.Both eyes may look in different directions when focusing on an object.
• Cataracts. The lens of the eye becomes blurry.

Your dominant eye may switch after cataract surgery and other vision surgeries. Usually, your eye surgeon can set which eye you’ll use for distance vision and which eye you’ll use for near vision. Doctors don’t know why eye dominance sometimes changes after these surgeries.

Can Eye Dominance Be Corrected?

There’s no need to correct eye dominance. It’s a normal part of how your brain and vision work. 

Exercises to strengthen your nondominant eye

If both your eyes are healthy and working well, there’s no need to strengthen your nondominant eye, says Meenal Agarwal, an optometrist in Ontario, Canada. “But if you want to improve balance or performance, speak to your optometrist and consider vision therapy, patching the dominant eye, targeted visual exercises, and mindful binocular tasks,” she says. “Remember, these should be under your eye doctor’s supervision, as sometimes, these can weaken your dominant eye if performed incorrectly.”

Takeaways

Your dominant eye is the one your brain relies on more than the other. Most of the time, it’s on the same side as your dominant hand. It’s a common and normal part of how your eyes and brain communicate.

Eye dominance isn’t something that needs to be corrected in adults. But an optometrist or ophthalmologist can treat children whose dominant eye is affected by amblyopia (“lazy eye”). An eye doctor may take eye dominance into account when prescribing glasses, fitting contact lenses, or recommending surgical options.

Dominant Eye FAQs

Here are some commonly asked questions about eye dominance.

Is eye dominance present from birth, or does it develop over time?

There’s no clear eye dominance at birth. Early in your childhood, your brain starts to favor one eye for tasks such as reaching, drawing, or focusing. 

Does eye dominance change over time?

Once your brain favors one eye over the other, that’ll be your dominant eye. Usually, that doesn’t change. But if you’re injured, have vision loss in your dominant eye, or have eye surgery, it could cause your brain to switch and rely on your nondominant eye. For example, kids who get treatment for amblyopia may see a change in eye dominance.

Is it possible to not have a dominant eye?

Yes. Not everyone has a dominant eye.

Why should you aim with your dominant eye?

Your dominant eye can help you hit your mark in sports or tasks that need precision, such as archery, competitive shooting, or photography. This is especially true if your dominant eye is on the opposite side of your dominant hand.

Is it a disadvantage to be left-eye dominant?

Not necessarily. But it could pose a challenge in certain sports, such as competitive shooting or archery, especially if your dominant eye is opposite from your dominant hand. If this is the case, you can train to adapt or override your brain’s dominant eye preference.