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 the child has learning difficulties rather than an eye disorder.
Treatments are usually effective for convergence insufficiency.
Source: http://www.mayoclinic.com