What is Convergence Insufficiency?
Convergence insufficiency (CI) is a common eye disorder in which your eyes don’t work together to focus on objects in your near vision. While one eye is focused, the other is turned outward, resulting in double or blurry vision.
Eye muscles and nerves need to coordinate to look inward (converge) and focus on an object up close. When something interrupts this process, misalignment occurs and disrupts vision.
Convergence insufficiency is a binocular vision disorder that typically starts in childhood. One out of every 20 children has the condition. It can also occur after a brain injury or concussion. An estimated 2 to 13 percent of people in the United States live with CI, but the condition is often undiagnosed.1
Symptoms of Convergence Insufficiency
Symptomatic convergence insufficiency disrupts focus on close-up objects. It can interfere with near-vision activities, such as reading, writing, and looking at a smartphone. It is not associated with distance vision disturbances.
Double vision and blurred vision are the most common side effects of CI, but other symptoms may be present, including:
- Sore or tired eyes
- Trouble focusing
- Eye strain
- Headaches
- Inability to concentrate
- Squinting
- Frequent head tilt
- Motion sickness or vertigo
- Trouble reading
Poor depth perception is also a complication of convergence insufficiency due to one eye doing all the work. This complication can impact:
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Sports, especially those that involve catching or hitting balls
- Avoiding eye contact
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Judgment of distances, resulting in frequent trips, falls, or bumps into things
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Poor posture when using near vision
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Reading, as words look like they are moving, floating, or jumping
What Causes Convergence Insufficiency?
Convergence insufficiency can result from nerve damage due to brain injury or trauma. But the cause of CI in people who do not have a history of nerve damage is unclear.
Convergence insufficiency tends to run in families. It is also associated with health conditions that stem from a nerve or autoimmune disorder, such as:
Prolonged computer use, playing video games longer than 4 hours, and visually demanding jobs also increase a person’s chances of developing CI.6
When to See a Medical Professional
Doctors cannot detect convergence insufficiency during routine vision screenings. Therefore, CI can go undiagnosed. Many people with CI have normal 20/20 vision, which can delay treatment.
Because there are no visible signs of CI, children, and adults with chronic CI symptoms should consult an eye doctor for a comprehensive eye exam.
Diagnosis
A licensed ophthalmologist or optometrist diagnoses convergence insufficiency during a comprehensive eye exam. During the exam, the eye doctor takes a detailed health history and asks about any symptoms.
A series of eye exams can determine if you have CI. The following criteria are often associated with a convergence insufficiency diagnosis:
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Large exophoria. Eye(s) turn outward instead of inward at near.
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Reduced near point convergence. Measures the distance you can hold your eyes together without having double vision.
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Decreased fusional vergence amplitude. Amount of prism tolerated before getting double vision.
Treatment
The most effective way to treat convergence insufficiency is through vision therapy.
Vision therapy is a series of eye exercises that strengthen communication between the brain and eyes. A person diagnosed with CI will do in-office and at-home exercises with the help of a licensed eye professional.
Common convergence exercises include:
- Pencil push-ups for eye tracking
- Depth perception practice
- Computer program vision therapy
A combination of both in-office and at-home exercises are typically the most effective way to correct CI, but the types of convergence exercises prescribed will depend on:
- Age
- Proximity to the vision center
- Exercise preferences
- Cost
It may take up to 12 weeks to see an increased convergence ability from vision therapy, so it is essential to be patient and comply with your eye doctor’s treatment plan. If vision therapy doesn’t improve symptoms over time, prism glasses may be necessary. In rare cases, eye doctors might recommend surgery.
Complications
If left untreated, convergence insufficiency can lead to visual suppression or other severe eye disorders such as amblyopia (lazy eye) and strabismus (eye turn).
Children who progress through life with undiagnosed and untreated convergence insufficiency may struggle with:
- Coordinated sports
- Reading
- School work
- Attention disorders
- Frequent accidents
These children might also receive an incorrect diagnosis for a learning disability. Their self-esteem and self-confidence may also suffer if they believe they are unable to enjoy the same activities as their peers.
Scheduling a routine, comprehensive eye exam each year can help eye doctors catch common vision disorders before they become serious.
Outlook
As long as your doctor correctly diagnoses CI and you comply with your vision therapy and prescription treatment plan, the outlook for correcting CI is positive. The key is to understand the signs and symptoms early on and visit your eye doctor for a comprehensive eye exam.
Scientists are actively researching new convergence eye exercises and ways to implement virtual reality into future CI treatments.
Prevention
Convergence exercises and vision therapy are the most effective ways to correct CI before complications occur. Because the exact cause of CI is often unknown, it can’t be prevented.
And because convergence insufficiency is not diagnosed during routine eye exams, many people may not know they have the condition. Reporting symptoms to an eye doctor right away is the best way to prevent CI from harming your vision.
Summary
Convergence insufficiency is a common childhood eye condition that disrupts the eyes’ ability to move inward while looking at objects close up. This results in double and blurred vision. The exact cause is unknown, but it has been associated with health conditions that affect nerve coordination.
Because people can pass a routine vision screening while having CI, it often goes undiagnosed. If left untreated, CI can lead to other eye complications and interfere with critical daily activities such as reading, playing sports, and making eye contact.
CI is prevalent in school-age children, and therefore, it, along with other vision disorders, are frequently misdiagnosed as learning disabilities. To avoid delays in learning, it is essential to get your child a comprehensive eye exam if they complain of CI symptoms.
Eye doctors effectively correct convergence insufficiency with vision therapy. If symptoms don’t improve over a few weeks, base prism eyeglasses may be prescribed. Surgery is a last resort treatment alternative.
If you or your child experience vision symptoms associated with convergence insufficiency, contact your eye doctor right away.
