Convergence Insufficiency

A child with difficulty reading and doing homework

What is Convergence Insufficiency?

Eyestrain, headaches, blurred vision, and concentration problems can be symptoms of a vision disorder called convergence insufficiency (CI). The disorder affects both adults and children and can make reading particularly challenging.

CI Is a Teamwork Issue

Your ability to focus on a puzzle, game or the words on a page or computer depends on the ability of your eyes to work together as a team. As you read or perform other tasks that require near vision, both of your eyes must turn inward slightly.

If you suffer from CI, your eyes may not align properly when you look at close objects. This makes it difficult for your brain to produce a single clear image from the light impulses it receives from each eye. Even slight variations in eye alignment can cause CI symptoms. In some cases, the brain may eventually ignore the signals from one of your eyes, causing depth perception issues and other problems.

CI symptoms can also occur if you've had a stroke or have Parkinson's disease.

How Can I Tell if I have CI?

CI causes a variety of symptoms, including several that may not seem to be associated with your vision at first glance. If you have CI, you may experience:

  • Discomfort. Eyestrain and headaches are common and may occur fairly soon after you start an activity that requires good near vision.
  • Blurred Vision. Both blurred and double vision may occur. These symptoms can become worse the longer you read or focus on near objects.
  • Difficulty Concentrating. Do you joke about your short attention span? Trouble concentrating or remembering what you've just read can occur if it's difficult to read or focus on near objects due to CI.
  • Moving Words. Words seem to move or jump on the page when your eyes have a teaming issue.
  • Motion Sickness. Motion sickness or vertigo may not be an inner ear problem but might be related to a vision disorder.
  • Fatigue. Reading or working on the computer can be exhausting due to your disorder.
  • Closing One Eye. People who CI may find it easier to rely on one eye rather than both for close tasks. If you can see better if you squint or cover one eye when you read, you may have CI.
  • Poor Grades or Conduct. Your child's grades or conduct may suffer if he or she has CI.

If you suspect you have CI, schedule a comprehensive vision examination with a vision therapist. In addition to determining your visual acuity, your ability to read letters on an eye chart, your vision therapist will conduct other tests to determine if you have a vision disorder. These tests evaluate eye teaming, depth perception, the muscles that control eye movements, and other aspects crucial to good vision.

How Is CI Treated?

Vision therapy offers an effective treatment option for CI. The therapy enhances the pathways between the eyes and the brain and also improves eye muscle strength and coordination.

During therapy, you'll participate in activities and games that help you focus on close activities. Depending on your treatment plan, you might play a computer game that gradually trains your eyes to work together, wear prism lenses, or call out the letters you see on a swinging ball.

For years, a type of vision exercise called pencil push ups was one of the standard treatments for CI. In a National Eye Institute-funded study, researchers compared the effectiveness of pencil push ups versus vision therapy. They discovered that 75% of participants who received in-office vision therapy and at-home reinforcement activities had normal vision or far fewer CI symptoms after three months of treatment.

Only 43% of participants who received home-based therapy and 33% who performed pencil push ups and computer therapy had similar results.

Vision therapy is particularly helpful in treating children with CI, but it's also a good option for adults. Although it was once believed that adult brains became less plastic or changeable over time, several studies have proven that adults brains have more plasticity than researchers expected.

Do you think you or your child may have convergence insufficiency? We can help you improve your vision. Contact us to schedule a comprehensive eye exam.


Optometrist’s Network: What is Convergence Insufficiency?

College of Optometrists in Vision Development: Convergence Insufficiency

National Eye Institute: More Effective Treatment Identified for Common Childhood Vision Disorder

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