Dominant Eye: How to Check.

Naturally, we use both our eyes to see things simultaneously, but one of our eyes is usually the dominant or preferred eye. You can test which eye is dominant with a simple method as follows:

1. Extend both of your arms in front of you, forming a triangular opening with your hands, and aim at an object.
   
   
2. Test your vision by closing one eye at a time.

If you see the object within the triangular opening while keeping both eyes open, it means that the eye you closed is the dominant eye. On the other hand, if you close one eye and notice that the object shifts or moves partially out of the triangular opening, that eye is your non-dominant eye.

• If closing your left eye keeps the object within the triangle but closing your right eye causes it to shift or disappear from the triangle, your right eye is dominant.
  
  
• Conversely, if closing your right eye keeps the object within the triangle but closing your left eye causes it to shift or disappear, your left eye is dominant.

This is a simple and self-administered method to determine your dominant and non-dominant eyes. In summary, when you look through your joined hands forming a triangular opening and close one eye, the eye that allows you to see the object you aimed at is your dominant eye.

What Is a Dominant Eye?

The dominant eye, or “ocular dominance,” refers to the eye that provides a slightly stronger input to the visual cortex of the brain and is relied upon more heavily when looking at objects, particularly in tasks that require precision, such as aiming, photography, or using a microscope.

Just as most people have a dominant hand, they also have a dominant eye. While both eyes work together to create a single visual image, the dominant eye typically aligns more directly with the object you're focusing on, especially during tasks requiring monocular vision.

How Does Eye Dominance Work?

Eye dominance does not always correspond to handedness—right-handed individuals may be left-eye dominant and vice versa. Dominance occurs when one eye leads visual input slightly more efficiently, offering sharper or faster perception under certain circumstances.

It becomes particularly important in:

• Sports (e.g., archery, golf, shooting)

• Photography and videography

• Refractive surgery planning (e.g., monovision LASIK)

• Contact lens fitting, especially for presbyopia correction

• Neurological assessments

• Certain eye conditions (e.g., amblyopia)

How to Test for Your Dominant Eye

Testing for your dominant eye can be done easily at home using a few simple techniques. These tests are non-invasive and take just a few minutes:

The Triangle Test (Miles Test)

1. Extend your arms and create a triangle-shaped opening between your thumbs and index fingers.

2. With both eyes open, focus on a distant object through the triangle (like a clock or doorknob).

3. Slowly bring your hands back toward your face while maintaining focus on the object.

4. The triangle will naturally align with your dominant eye.

The Hole-in-the-Card Test

1. Cut a small hole (about 1 inch wide) in a piece of paper.

2. Hold the paper with both hands and look at a distant object through the hole with both eyes open.

3. Bring the paper toward your face—your dominant eye will align with the hole.

The Pointing Test

1. With both eyes open, point to a distant object with your index finger.

2. Close one eye at a time.

3. The eye that keeps your finger directly aligned with the object is your dominant eye.

Importance of Knowing Your Dominant Eye

Understanding your dominant eye helps optimize performance in both daily and professional activities. Some key examples include:

Vision Correction and Surgery

• Monovision LASIK: One eye is corrected for distance and the other for near vision. The dominant eye is typically corrected for distance.

• Contact lens fitting: Especially relevant when using multifocal lenses or undergoing orthokeratology.

Sports and Performance

• Improves alignment in target sports (shooting, archery)

• Helps athletes and coaches develop individualized training strategies

Photography and Filming

• Aids in camera viewfinder alignment

• Reduces eye strain during extended shoots

Amblyopia and Eye Coordination

• In eye conditions like "lazy eye," dominance assessment is crucial for managing treatment and therapy

Eye Dominance vs. Eye Strength

It’s important to note that having a dominant eye doesn’t necessarily mean it has better vision. One eye may be optically stronger (better visual acuity) but not dominant neurologically.

Conversely, the dominant eye may be slightly weaker in sharpness but still plays the lead role in visual processing and alignment.

What If You Have No Clear Dominant Eye?

Some individuals have co-dominance, meaning both eyes work equally well without a clear preference. Others may switch dominance depending on the activity. This flexibility is generally not a concern unless you're undergoing eye surgery or fitting specialized lenses.

Diagnosis and Eye Evaluation at Bangkok Eye Hospital

If you’re considering vision correction procedures or experiencing difficulties with binocular vision, determining your dominant eye is a vital part of the assessment. At Bangkok Eye Hospital, we offer advanced diagnostic and screening services including:

• Comprehensive eye examinations

• Ocular dominance testing

• Refractive error assessments

• Binocular vision and alignment evaluations

• Pre-operative planning for LASIK and ICL

• Contact lens fitting consultations

All tests are conducted by experienced ophthalmologists and optometrists using high-precision equipment.

Related Services at Bangkok Eye Hospital

We provide a range of services to support vision correction, diagnosis, and training that incorporate knowledge of eye dominance:

• LASIK & Refractive Surgery Center
  Advanced laser treatments, including monovision correction tailored to eye dominance

• Contact Lens Clinic
  Precision fitting for single vision, multifocal, and monovision contact lenses

• Binocular Vision and Strabismus Clinic
  Treats issues with eye alignment, muscle balance, and visual tracking

• Pediatric Eye Care
  Early detection of dominant eye patterns and treatment for amblyopia

• Vision Training Programs
  For athletes, students, and professionals needing performance optimization

Frequently Asked Questions (FAQs)

Can my dominant eye change over time?
In rare cases, eye dominance may shift due to vision loss, trauma, or neurological changes. However, most people retain the same dominant eye throughout life.

Is eye dominance related to handedness?
Not directly. While many people are right-eye and right-hand dominant, cross-dominance is common and normal.

Do I need to know my dominant eye before LASIK?
Yes. For procedures like monovision LASIK, it’s critical to identify the dominant eye to determine which one to correct for distance vision.

Can I train my non-dominant eye to become dominant?
Not typically. However, you can improve binocular coordination and strength through vision therapy, especially in children with amblyopia or alignment issues.

Does dominant eye testing hurt or require special tools?
No. The tests are simple, painless, and can often be done at home or during a routine eye exam.