You probably know whether you’re right-handed or left-handed. But have you ever wondered whether you’re right-eyed or left-eyed?
Most people have an eye they naturally prefer for certain visual tasks, like aiming at a target. This is commonly called your dominant eye, and you can figure out which one it is with a simple test that takes about 10 seconds.
What’s even more interesting is that your dominant eye doesn’t necessarily match your dominant hand. You can be right-handed and left-eye dominant, left-handed and right-eye dominant, or have a relatively weak preference between the two.
So, why is one eye dominant over the other? And does having a dominant eye mean there’s something different about your vision?
Here’s what you should know.
What Is a Dominant Eye?
Your dominant eye is generally the eye your visual system tends to favor for certain tasks, particularly when you need to line something up or determine its position.
You may also hear this referred to as ocular dominance or eye preference.
That doesn’t mean you’re walking around primarily seeing through one eye. Under normal circumstances, your brain is constantly combining information from both eyes to create one visual experience. The small differences between what each eye sees also help your brain perceive depth.
Eye dominance is a little more complicated than simply having one eye that does all the work. In fact, researchers recognize different types of ocular dominance, and the eye you favor can sometimes depend on the task.
For everyday purposes, though, when people talk about a dominant eye, they’re usually talking about the eye they naturally use when aiming or looking through a small opening.
How to Tell Which Eye Is Dominant
Want to try a quick dominant eye test?
Pick an object across the room, such as a doorknob, light switch, or picture on the wall.
- Hold your arms straight out in front of you with your hands up (like you’re going to push against a wall) and your fingers close together.
- Bring your hands together and make a small triangle between your thumbs and index fingers.
- Keep both eyes open and center the distant object inside the triangle.
- Close your left eye.
- Open it, then close your right eye.
With one eye, the object should stay relatively centered inside the opening. With the other, it will appear to jump out of place.
The eye that keeps the object centered is typically your sighting-dominant eye.
You can also do a similar test by looking at an object through a small hole in a piece of paper.
Surprised by your result? You might be, especially if the eye you favor is on the opposite side from your dominant hand.
Why Is One Eye Dominant?
We tend to think of our eyes as two cameras sending identical pictures to the brain, but that isn’t quite how vision works.
Each eye sees the world from a slightly different angle. Your brain takes those two streams of visual information, processes them, and combines them into the single image you perceive.
Within that system, the brain may favor information from one eye more than the other in certain situations. That preference is what we describe as ocular dominance.
And it isn’t necessarily an all-or-nothing trait.
Some people have a strong preference for one eye, while others have relatively balanced eyes. Your dominant eye can also vary depending on exactly how it is being measured.
So, rather than thinking of one eye as the “good eye” and the other as the “bad eye,” it may be more helpful to think of eye dominance as one part of how your brain manages information coming from two eyes.
Why Does Eye Dominance Matter?
Most of the time, you don’t need to know which eye is dominant. Your brain has been handling the arrangement perfectly well without you thinking about it.
But there are situations where eye dominance can be useful information.
Contact Lenses
Eye dominance can become particularly relevant when we use monovision contact lenses for people who are beginning to have difficulty focusing up close.
With monovision, one eye is generally corrected more for distance while the other is corrected more for near vision. Determining eye dominance can be one piece of deciding how to set up that correction.
However, the simple dominant eye test you perform at home doesn’t tell us everything we need to know. There are different ways to evaluate ocular dominance. However, a basic sighting test doesn’t always match how a person’s visual system responds under simulated monovision conditions.
That’s one reason we evaluate how the eyes actually work together rather than relying on a single test.
RELATED CONTENT: Pros and Cons of Contact Lenses
Sports & Other Activities
Eye dominance may also come up in activities that require you to align your vision with a target, such as archery, shooting sports, or looking through a camera viewfinder.
You may naturally bring a camera, telescope, or other viewing device toward your dominant eye without ever realizing you’re doing it.
That doesn’t mean being cross-eye dominant makes someone worse at sports or that you need to retrain one of your eyes. It simply helps explain why certain positions or movements may feel more natural.
FAQs on Eye Dominance
Can You Be Right-Handed and Left-Eye Dominant?
Absolutely. Being right-handed and left-eye dominant is an example of cross-dominance, sometimes called crossed dominance. The same thing can happen if you’re left-handed but favor your right eye.
Your dominant hand and dominant eye don’t have to match because handedness and ocular dominance are not the same neurological process.
There is some association between handedness and eye preference across populations, but it’s far from a one-to-one relationship. Cross-dominance is common enough that discovering your dominant eye is opposite your dominant hand isn’t unusual.
So if you write with your right hand but your left eye won the test above, there’s no reason to try to “correct” it. That’s simply how your visual system prefers to operate.
Does Your Dominant Eye Have Better Vision?
Not necessarily. This is one of the biggest misconceptions about eye dominance. Your dominant eye isn’t automatically the eye with the better prescription, sharper eyesight, or healthier eye.
Visual acuity tells us how clearly each eye can see. Eye dominance tells us something different: which eye your visual system tends to favor under certain circumstances.
That means you could have 20/20 vision in both eyes and still have a clear dominant eye. You could also have a stronger prescription in your dominant eye.
During an eye exam, we evaluate each eye individually as well as how the two eyes work together. Simply knowing which eye is dominant doesn’t tell us which eye “sees better.”
Can Your Dominant Eye Change?
Eye dominance isn’t always as fixed as being right-handed or left-handed.
For some people, the preference is very strong and consistent. For others, it may be relatively weak or even change depending on the task or how dominance is tested.
Factors such as differences in contrast, prescription, viewing distance, and the specific visual task can affect which eye is favored.
Final Thoughts
Knowing your dominant eye is mostly an interesting glimpse into something your brain has been doing behind the scenes all along.
If you’ve noticed a new difference between your eyes, one eye suddenly seems much blurrier than the other, you experience double vision, or you feel like you’re relying heavily on one eye because the other doesn’t see well, that’s different from normal eye dominance and is worth having evaluated.
Next time you’re sitting around with friends or family, try the dominant eye test. You may be surprised to find out who’s right-eyed, who’s left-eyed, and whose dominant eye doesn’t match their dominant hand.
