Overview

Convergence insufficiency is a condition in which your eyes are unable to work together when looking at nearby objects. This condition causes one eye to turn outward instead of inward with the other eye, creating double or blurred vision.

Convergence insufficiency is usually diagnosed in school-age children and adolescents. It can cause difficulty reading, for which parents or teachers might suspect that the child has learning difficulties rather than an eye disorder.

People of all ages may have convergence insufficiency diagnosed after a concussion or traumatic brain injury.

Treatments are usually effective for convergence insufficiency.

Symptoms

Not everyone with convergence insufficiency has signs and symptoms. Signs and symptoms occur while you're reading or doing other close work and might include:

Tired, sore or uncomfortable eyes (eyestrain)

Headaches

Difficulty reading — words seem to float on the page, you lose your place or you read slowly — which might cause you to avoid reading or not complete schoolwork

Double vision (diplopia)

Difficulty concentrating

Squinting, rubbing or closing one eye

When to see a doctor

If you or your child has symptoms of convergence insufficiency or problems reading, consult an eye care professional — an ophthalmologist or an optometrist.

Causes

The cause of convergence insufficiency isn't known, but it involves a misalignment of the eyes when focusing on nearby objects. The misalignment involves the muscles that move the eye. Typically, one eye drifts outward when you're focusing on a word or object at close range.

Complications

Difficulties with reading and concentrating can affect a child's learning. Convergence insufficiency does not cause learning disabilities, but it makes using your eyes difficult and tiring.

Convergence insufficiency typically isn't detected in routine eye exams or school-based vision screenings. Reading difficulties of children with the condition might lead to an evaluation for learning disabilities, but it's important to rule out this eye disorder.