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

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.

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.