Convergence Insufficiency

What is convergence insufficiency?

Convergence insufficiency is a vision disorder involving binocular vision, which is vision using both of your eyes.

“Convergence” describes the way your eyes move together and point inward when you look at nearby objects, such as books, tablets or smartphone screens. With convergence insufficiency, there’s an eye coordination problem, in which your eyes instead drift outward as you look at objects close-up. This can cause double or blurred vision.

Convergence insufficiency typically starts in childhood, but often goes undiagnosed. Healthcare providers who do diagnose it often identify the condition when children are learning to read. Convergence insufficiency in adults can also occur after a brain injury, like a concussion.

How common is convergence insufficiency?

Convergence insufficiency occurs in an estimated 2% to 13% of people in the U.S.

What are the symptoms of convergence insufficiency?

People with convergence insufficiency may experience several symptoms when reading or looking at objects close-up, like books or smartphones. Convergence insufficiency symptoms may include:

• Headache.
• Double vision (diplopia).
• Tired or sore eyes.
• Blurry vision.
• Difficulty concentrating.
• Squinting, closing or rubbing an eye.
• Dizziness.

What are the causes of convergence insufficiency?

A lack of communication between your nerves and the muscles that control your eye movements causes convergence insufficiency. Your eye muscles themselves are healthy, but the nerves that control them aren’t sending the proper message to your eyes to turn inward enough to aim at a close object. Instead of coming together to focus on near objects, one or both eyes remain pointing away from the target.

In some cases, a brain injury or neurodegenerative disease, such as Parkinson’s disease, can cause the condition.

What are the risk factors for this convergence insufficiency?

People with brain injuries often develop convergence insufficiency. Healthcare providers haven’t identified any other risk factors.

What are the complications of convergence insufficiency?

Most of the complications associated with convergence insufficiency relate to the discomfort it creates and the interference with activities that require near vision.

In some people with convergence insufficiency, your brain suppresses (shuts down) vision in one eye to avoid experiencing double vision. This is your brain’s answer to dealing with your eyes not working as a team. Or your eyes may drift farther apart and start working independently instead of together. This can lead to problems beyond discomfort, including:

• Lack of coordination.
• Poor judgment of distances.
• Trouble playing sports.
• Difficulty making eye contact.
• Motion sickness.

How is convergence insufficiency diagnosed?

Eye specialists called optometrists or ophthalmologists diagnose convergence insufficiency. They take your medical history and perform a complete vision exam.

A routine eye exam with the familiar 20/20 eye chart doesn’t diagnose convergence insufficiency. People can pass the standard eye exam even if they have convergence insufficiency.

A specialized convergence insufficiency test measures the ability of your eyes to converge when looking at an object as it moves closer to your face.

How is convergence insufficiency treated?

Convergence insufficiency treatment involves eye movement exercises that retrain your nerves to aim your eyes properly. These convergence insufficiency exercises improve your eyes’ ability to move inward together by focusing on objects at different distances. They may be performed with a specialized optometrist or a therapist in your provider’s office and repeated at home.

Occasionally, people require a special type of glasses called prism glasses. These glasses redirect the light entering your eyes. Basically, prism glasses do the work that your nerves don’t know how to do.

Rarely, surgery can help make your eye muscles stronger. Regular eyeglasses and eye patches usually don’t improve the condition.

How soon after treatment will I feel better?

You may not notice an improvement right away. It can take three months or more to notice a change in your vision. Typically, the results are permanent, but your symptoms may come back after:

• Not getting enough sleep.
• Being sick.
• Doing a lot of close-up activities.

Can this be prevented?

Because healthcare providers don’t know what causes the poor muscle coordination of convergence insufficiency, you can’t prevent it.

What can I expect if I have this condition?

Most people who undergo eye exercise treatment for convergence insufficiency experience fewer symptoms and improved vision.

When can I go back to work/school?

People with convergence insufficiency can go back to their normal activities immediately. With treatment, close-up activities such as reading and studying will become more comfortable.

When should I see my healthcare provider?

Contact your child’s healthcare provider if they experience symptoms of convergence insufficiency when doing up-close work like reading.

What questions should I ask my healthcare provider?

If you or your child have convergence insufficiency, you may want to ask your provider:

• Have you performed the necessary test to diagnose the condition?
• Can you refer me to someone who can administer the exercise treatments?
• How long will treatment take?
• Can the condition return?
• How can I prevent it from returning in the future?

Is convergence insufficiency related to ADHD?

Children being tested for attention-deficit/hyperactivity disorder (ADHD) frequently have an eye exam as part of their evaluation. The symptoms of convergence insufficiency often overlap with those of ADHD and can make it hard for children to concentrate on focused reading.

A 2005 study evaluated the link between convergence insufficiency and ADHD. This study stated that all children with an ADHD diagnosis should be examined for convergence insufficiency as well. This is because, compared to the general U.S. population, convergence insufficiency happens three times as often in children with ADHD.