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What is Convergence Insufficiency?

Convergence insufficiency is a condition in which eyes are unable to function together when looking at nearby objects. Our brain combines information it receives from both eyes to see objects clearly and in a single image.

The eyes must converge and focus on the same point. To preserve convergence and eye alignment when objects become closer to the face, the eyes must bend inward. Individuals with CI have difficulty converging and keeping eye alignment. Their eyes tend to drift away instead of staying properly aligned when attempting to focus on close-up tasks.

What is convergence insufficiency?

Eye Convergence

Ocular convergence, also known simply as convergence, refers to the coordinated movement of both eyes inward to focus on a nearby object. This crucial process allows us to maintain clear and sharp vision of objects that are close to us.

When we look at something nearby, the muscles in our eyes contract to direct both eyes towards the point of focus, enabling us to perceive details accurately. Convergence is an automatic ocular function essential for everyday activities such as reading, writing, and working on a computer.

However, certain vision problems can affect the eyes’ ability to converge properly, leading to eye strain and difficulty seeing up close.

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How Common is Convergence Insufficiency?

Convergence insufficiency is one of the most common vision conditions, as it affects as many as up to 17% of individuals (children and adults). The condition is more commonly found in children and young adults, and it may be underdiagnosed or misdiagnosed, as some individuals may not realize they have the condition or attribute their symptoms to other factors.

Convergence Insufficiency Symptoms

The symptoms of CI can vary from person to person, and they may not always be immediately apparent. Some of the common signs and symptoms include:

  1. Eye Strain:
    Feeling tired or uncomfortable after short periods of reading or screen time.
  2. Double Vision:
    Seeing multiple images or text overlapping when looking at close objects. Double or blurred vision occurs because one eye is incapable of turning inward to the required level.
  3. Blurred Vision:
    Experiencing difficulty in maintaining clear vision, especially during near tasks.
  4. Headaches:
    Frequently experiencing headaches, often centered around the eyes or forehead.
  5. Eyestrain in Specific Situations:
    Symptoms worsen during activities that require sustained focus, like reading or using digital devices. When reading or conducting near work activities for lengthy periods of time, people with CI frequently experience hazy or double vision, eye strain, and pain.
  6. Eye Fatigue:
    Sensation of tired, achy, or heavy eyes, especially after engaging in close-up work for extended periods.
  7. Motion Sickness:
    Feeling nauseous, dizzy, or unwell when exposed to motion or movement, particularly during activities like reading or driving.
  8. Reduced Reading Efficiency:
    Struggling with reading speed and comprehension, and needing to re-read things due to visual discomfort. Individuals have trouble concentrating on what they are reading, words seem to move, jump, or float on the page, motion sickness or vertigo.

Convergence Insufficiency Causes

The specific cause of convergence insufficiency is unknown. However, it is believed to be related to a combination of factors, including:

  1. Eye Muscle Imbalance:
    Weakness or poor coordination of the muscles responsible for eye convergence.
  2. Genetics:
    There may be a genetic predisposition to developing CI.
  3. Prolonged Near Work: Excessive use of digital devices, reading, or other close-up tasks can contribute to the development of CI.
  4. Trauma or Neurological Factors:
    In some cases, head injuries or neurological conditions may be associated with CI. Infection, traumatic brain injury, certain drugs, neurodegenerative illnesses, myasthenia gravis, or Graves ophthalmopathy can all cause convergence insufficiency.

How is Convergence Insufficiency Diagnosed?

Convergence insufficiency is typically diagnosed through a comprehensive eye examination performed by an eye care professional, such as an optometrist or ophthalmologist. The diagnostic process may include the following steps:

  1. Symptom Assessment: The eye care provider will begin by asking the patient about their symptoms and any difficulties they may be experiencing with near vision tasks, such as reading or using electronic devices.
  2. Visual Acuity Testing: This test assesses how well the patient can see at various distances using an eye chart. It helps determine if there are any issues with visual clarity.
  3. Binocular Vision Assessment: Binocular vision refers to the ability of the eyes to work together as a team. Tests such as the cover test and the alternating cover test are commonly used to assess binocular vision and detect any misalignment of the eyes.
  4. Near Point of Convergence (NPC) Test: This test measures the point at which the eyes begin to diverge or lose alignment when focusing on a near object. The patient is asked to focus on a small target (such as a pen tip or a small letter) as it is moved closer to their nose until they experience double vision or the eyes deviate outward.
  5. Convergence Amplitude Measurement: This test measures the ability of the eyes to converge fully when focusing on a near object. It helps determine the range of convergence and whether it falls within normal limits.
  6. Accommodation Assessment: Accommodation refers to the ability of the eyes to focus on objects at different distances. Testing accommodation can help identify any issues with focusing ability that may be contributing to convergence insufficiency.
  7. Additional Testing: Depending on the individual case, additional tests such as a comprehensive eye health evaluation or specialized imaging tests may be performed to rule out other potential causes of vision problems.

To be able to precisely diagnose CI, a doctor should take at least the measurements of the near point of convergence, exodeviation, accommodation, and positive fusional vergence.

Convergence Insufficiency Test at Home

While a comprehensive evaluation by an eye care professional is the most reliable way to diagnose eye convergence problems such as convergence insufficiency, there is one simple test you can perform at home that may indicate potential issues.

Near Point of Convergence Test (NPC):

  • Hold a small object, such as a pen or pencil, at arm’s length and focus on it.
  • Slowly bring the object closer to your nose while maintaining focus.
  • Stop when you notice that the object appears to double, blur, or drift apart.
  • Measure the distance between your eyes and the object when these symptoms occur. Normally, this distance should be around 6 centimeters or less. If you find it’s significantly farther away, it could indicate convergence insufficiency.

Convergence Insufficiency Treatment

The good news is that convergence insufficiency can be treated effectively.

Vision Therapy

Vision Therapy: The main treatment for convergence insufficiency is vision therapy. According to the findings of a study conducted by the Convergence Insufficiency Treatment Trial Group, vision therapy is the most effective method for improving both convergence and patient symptoms.

Vision therapy is a personalized program of eye exercises and activities designed to strengthen the eye muscles and improve eye teaming skills. Vision therapy aims to retrain the brain-eye connection, allowing the eyes to work together more efficiently.

Home Therapy Programs

Nowadays, there exist computer programs, such as AmblyoPlay, that can help enhance convergence ability and track progress over time. Symptoms usually go away once you’ve done the exercises on a regular basis for a short amount of time.

Brock String Exercises

Brock string is a tool used in vision therapy where a string with multiple colored beads is hung vertically. The patient focuses on different beads while moving them closer or farther away, which helps improve convergence abilities.

Brock String vision therapy tool

Pencil Push-Ups

Pencil Push-Up is a specific exercise where the patient holds a small object, such as a pencil, at arm’s length and gradually brings it closer to the nose while maintaining focus. This helps strengthen the eye muscles responsible for convergence.

Prism Lenses

Furthermore, eye doctors frequently recommend certain eye exercises. Looking through prisms could be one of these exercises. However, the prism lens approach is only used when a person is unable or unsuccessful in undergoing vision therapy.


Due to the effectiveness of vision therapy, surgery is rarely considered.

Can Eye Patching Help for Convergence Insufficiency?

Covering one eye with eye patch does not help with CI correction because it does not allow you to practice working with both eyes simultaneously. However, it may temporarily alleviate symptoms.

Convergence Insufficiency Exercises App: AmblyoPlay Success Stories

Yes, AmblyoPlay is also a vision therapy for convergence insufficiency.

AmblyoPlay treats convergence insufficiency
Delta, OH

Havilah: “We have seen great progress.”

My daughter used this to help her with her convergence insufficiency. After six months of use, we have seen great progress. Six months of Optical Therapy was going to cost our family over $3,000. This number was astronomical for our family who had been hit hard during this pandemic. We are very thankful to have found something affordable and so easy to use. She loves playing the games. I appreciate the assessments that are done regularly and the feedback is good too. Thanks Amblyoplay!

I highly recommend AmblyoPlay for convergence insufficiency.
Brandon, FL

Olivia: “I highly recommend AmblyoPlay.”

My experience with AmblyoPlay has been very good. I have a convergence insufficiency which has affected my ability to read, which was a big problem for me. AmblyoPlay has helped a ton and I see a lot better. Consistency is key with training. You really have to train every day and can’t go weeks without training or else you won’t see the results you want. Overall, I highly recommend Amblyoplay.

I treated convergence insufficiency with AmblyoPlay and have no more migraines.
Boise, ID

Morgan: “No more migraines!”

No more migraines! My 10yo son was suffering from frequent migraines and has ADHD and dyslexia. He was diagnosed with convergence insufficiency, which was likely causing the migraines. 4 months of AmblyoPlay and his migraines were gone!

Get your AmblyoPlay Vision Therapy today!


As convergence insufficiency is not a condition that people could out-grow, it is present both in children and adults. According to research conducted by the Convergence Insufficiency Treatment Trial group, adults showed significant improvement after receiving office-based vision therapy.

According to the study, 50 percent of the adults claimed they had “improved vision” or had been “cured” after 12 weeks of treatment. The study concluded that with continued sessions, there may have been an increase in the number of adults with CI that showed improvement from vision therapy.

Based on these findings, research suggests that with a vision therapy program, adults with CI can still learn how to use their fusional convergence skills for clear, single vision. Vision therapy helps to improve eye muscle coordination and trains the brain to use the appropriate skills for precise and comfortable binocular vision. Convergence insufficiency can be successfully treated in adults as well!

Frequently Asked Questions

What is convergence insufficiency?

Convergence insufficiency is a condition in which eyes are unable to function together when looking at nearby objects.

How do I know I have convergence insufficiency?

You may suspect you have it if you experience any of the symptoms, such as eye strain, double vision, blurred vision, headache, eye fatigue, motion sickness, reduced reading efficiency, etc. Consulting with an eye care professional is recommended for proper evaluation and diagnosis.

What causes convergence insufficiency?

The exact cause of convergence insufficiency is not fully understood, but it is believed to be related to a combination of factors, including eye muscle imbalance, genetics, prolonged near work, trauma, and neurological factors.

Is there treatment for convergence insufficiency?

Convergence Insufficiency can be treated effectively. The most common and successful treatment for convergence insufficiency is vision therapy.

Can convergence insufficiency be treated with vision therapy?

Yes, vision therapy is the most common and effective treatment for convergence insufficiency.

What is AmblyoPlay?

AmblyoPlay is a vision therapy solution that is performed through playing therapeutic games and exercises on your tablet or computer for 30 minutes per day. With exercises that adapt to each patient and their specific needs, it is an ideal solution for problems such as lazy eye, strabismus, convergence insufficiency, double vision, or other binocular problems.

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Why Do We Suggest a Minimum Time of 6 Months for Success?

Based on the data from over 15,000 patients using AmblyoPlay, improvements start within 4 months, while optimal results take anywhere between 6-18 months on average. The duration of required training depends on the patient’s age, the severity of the problem, accompanying diseases, and adherence to the training program.