Convergence Insufficiency

What is Convergence Insufficiency (CI)?

Convergence insufficiency (CI) refers to an eye condition in which your eyes have a tendency to drift outward when looking at objects nearby. Your ability to converge (or to rotate your eyes toward each other) is limited.

For example, if you are reading a book, your eyes may struggle to focus on the text on the pages. You may see blurry or double. Or, if you are looking at a menu at a restaurant, you may have trouble seeing the options clearly.

If you have difficulty with certain eye movements, you may have convergence insufficiency. An eye care doctor will perform an eye exam on you to determine whether or not you have convergence insufficiency.

What Does Convergence Insufficiency Look Like?

When you are looking at something up close, your eyes typically turn inwards to focus. When you have convergence insufficiency, your eyes have difficulty with this task. Someone with normal vision would be able to move their eyes to look at the object that is close in distance.

If you have convergence insufficiency or other vision problems, talk to an eye doctor. They may be able to prescribe treatments and eye exercises to help you improve your eye muscle movements.

Convergence Insufficiency vs. Exotropia

Exotropia refers to a form of strabismus (or an eye misalignment) in which one or both of your eyes tend to turn outward. Exotropia is the opposite of esotropia (also known as crossed eyes). 

Convergence insufficiency is not as serious as exotropia. With CI, your eyes may have difficulty working together when observing close-by objects. But, with exotropia, your eyes may always turn outward.

What Causes Convergence Insufficiency?

The cause for convergence insufficiency varies. Some children and young adults may develop CI after getting a concussion or having another brain injury. Otherwise, the cause for CI is largely unknown.

People who have perfect vision can even develop convergence insufficiency. If you notice a difference in your eyesight, talk to your eye doctor. You may have a vision problem that is treatable.

Convergence Insufficiency Symptoms

The symptoms of CI include, but are not limited to, the following:

• The eyes look outward
• Difficulty focusing on an object that is nearby
• Blurred vision
• Double vision
• Headaches
• Eye strain or fatigue
• Trouble reading

The symptoms of convergence insufficiency vary from person to person, depending on how severe the case is. You may not notice it too much. Or you may notice it a lot and experience significant symptoms. 

How Common is CI?

CI is common in both children and adults. In fact, even people with 20/20 vision can get CI. Between four and 17 percent of children and adults have CI. But the reasons why some people get CI are unknown. Some people develop CI after suffering a concussion or another brain injury.

While CI typically starts in childhood, it can happen to anyone at any age. Without treatment, it can continue for years. That is why it is important to talk to your eye doctor about convergence therapy and treatment options for you.

Is Convergence Insufficiency Serious?

CI is quite common, and it is not always so serious. Simply, to see objects clearly and singularly up close, the brain needs information from both eyes. This requires your eyes to converge and focus on the same point. And, as the object moves closer to you, your eyes will need to turn inward.

If you cannot do this or have difficulty doing this, you may experience blurry or double vision, eye strain, and discomfort. This can take a toll on your day-to-day activities, and it can affect children learning to read. Therefore, while convergence insufficiency itself may not be serious, it can have severe impacts on your life.

Diagnosis: Convergence Insufficiency Test

In order to be diagnosed with symptomatic convergence insufficiency, your doctor will perform several visual tests on you, including close work with objects to see how your eyes react.

Specifically, to diagnose CI, your eye doctor must take the following measurements:

• Near point of convergence — the closest point to the face where your eyes continue to converge together.
• Positive fusional vergence — the neuromuscular ability of your eyes to converge inward.
• Exodeviation — the tendency for your eyes to drift outward.
• Accommodation — your eyes’ ability to change focus from far to near.

If you do not have convergence insufficiency, you may have another type of eye misalignment or vision issue that your doctor can treat. 

Why is CI Often Left Undiagnosed?

CI is often left undiagnosed because it is not always part of school optometry exams. Therefore, many children with CI may be misdiagnosed with another eye dysfunction or go undiagnosed.

Treatment for Convergence Insufficiency

There are a few ways to treat convergence insufficiency. Effective treatment of convergence insufficiency may vary depending on the severity of your condition.

Vision Therapy for Convergence Insufficiency

Convergence insufficiency may be treated with vision therapy, which works to normalize your eyes’ neuromuscular abilities to converge. This is known as positive fusional vergence. 

Vision therapy may include practice converging and focusing the eyes at different distances. Your eye doctor will use special equipment to stimulate and monitor your eyes’ alignment and convergence ability.

The most effective way to treat convergence insufficiency is in-office with additional at-home exercises. For example, most children who undergo in-office therapy show improvement or normal vision after 12 weeks.

- The NEI Convergence Insufficiency Treatment Trial (CITT) 

Do Glasses Help Convergence Insufficiency? 

Eyeglasses may help you better cope with symptoms of convergence insufficiency.

Specifically, one type of therapy to correct convergence insufficiency uses base-out prism glasses. Prism lenses help to realign the image with the position of your eye. But they are only used for short periods of time because they can be very tiring.

That said, using these glasses does not necessarily help you converge your eyes on your own. Glasses are basically a Band-aid fix for convergence insufficiency. They can help you deal with the symptoms and see better while you are wearing them. But they may not actually improve the problem at its root.

Convergence Insufficiency Exercises

Your optometrist or ophthalmologist may use several tools to force your eyes to converge. They may go through practices with you to exercise those eye muscles. For example, these may include exercises like pencil push-ups. 

Talk to your eye doctor about the best exercises and other treatments for you. You will likely have activities that you need to do in the office, as well as ones that you will have to do at home on your own.