Eye Dominance

Whether a righty or a lefty, we can all cite our hand preference. But do you know your preferred or dominant eye? Probably not. Because we generally use both eyes together, having a preferred eye is an often overlooked trait.

How Do You Know Which Eye Is Dominant?

You can find your dominant eye by looking through:

• a camera, telescope or microscope
• the sight of a rifle

Your chosen eye for these and other monocular (one-eyed) tasks is typically the dominant one. Eye dominance usually matches handedness—that is, you are more likely right-eye dominant if you are righthanded, for example. But sometimes the dominant eye opposes handedness.

There is also a simple test you can do without props:

• Form a circle with your hand and fully extend your arm in front of you.
• Look through your hand circle at a distance object, like a clock or a door knob.
• Close one eye and then the other, and take note of the object’s position.
• The object will stay centered with your dominant eye open.

If you still can’t tell, ask your ophthalmologist at your next eye exam. There are rare cases when neither eye is dominant.

Why Is Eye Dominance Important?

For most people, knowing their dominant eye is not a concern. And while your dominant eye is not always your best seeing eye, knowing which is yours is helpful when:

• Playing certain sports like golf, baseball and target shooting. Dominant eye use enhances performance in any sport requiring focus on a target. When the dominant eye opposes handedness, it can impact performance. If you discover this is true for you, there are adjustments you can make to compensate.
• Taking photographs. Setting up a shot with your non-dominant eye can result in a misaligned image.

How Does Eye Dominance Affect My Eye Care?

Your ophthalmologist tests for eye dominance when:

• Correcting your vision. When people get monovision, one eye is corrected for near vision and the other eye for distance vision. You can get monovision from LASIK or artificial intraocular lenses (IOLs), or glasses and contact lenses. With monovision, your doctor needs to know your dominant eye as it is typically chosen and corrected for distance vision.
• Treating amblyopia/strabismus. Children can be at risk for amblyopia (lazy eye) when there is a large difference in prescription between the eyes. If the vision is uncorrected, the brain “turns off” the weaker eye. When treating amblyopia, the dominant eye is patched, so the child learns to strengthen the weaker eye.

For the vast majority, eye dominance is a mere curiosity with no bearing on day-to-day living. What's more important is maintaining healthy, binocular (two-eyed) vision. See your ophthalmologist if you have any concerns about your eye health.