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 focuses, the other turns outward, resulting in double or blurry vision.
Eye muscles and nerves must 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. An estimated 2 to 13 percent of people in the U.S. 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
- Looking at a smartphone
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:
- Sports, especially those that involve catching or hitting balls
- Avoiding eye contact
- Judgment of distances, resulting in frequent trips, falls, or bumps into things
- Poor posture when using near vision
- 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:
- Graves’ disease
- Myasthenia gravis
- Parkinson’s disease
- Alzheimer’s disease
Prolonged computer use, playing video games longer than 4 hours, and visually demanding jobs also increase a person’s chances of developing CI.6
Convergence Insufficiency Diagnosis
A licensed ophthalmologist or optometrist diagnoses CI 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 CI diagnosis:
- Large exophoria. Eye(s) turn outward instead of inward at near.
- Reduced near point convergence. Measures the distance you can hold your eyes together without having double vision.
- Decreased fusional vergence amplitude. Amount of prism tolerated before getting double vision.
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.
Treatment for Convergence Insufficiency
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 the 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 is typically the most effective way to correct CI. 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 remain 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 of Convergence Insufficiency
If left untreated, CI 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 cannot enjoy the same activities as their peers.
Scheduling a routine, comprehensive eye exam each year allows eye doctors to catch common vision disorders before they become serious.
How to Prevent Convergence Insufficiency
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 immediately is the best way to prevent CI from harming your vision.
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. Scientists are actively researching new convergence eye exercises and ways to implement virtual reality into future CI treatments.
Summary
Convergence insufficiency is a common childhood eye condition. It disrupts the eyes’ ability to move inward while looking at objects close up. This results in double and blurred vision.
Eye doctors effectively correct convergence insufficiency with vision therapy. Base prism eyeglasses may be prescribed if symptoms don’t improve over a few weeks. 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.
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