Convergence Insufficiency is the reduced ability for both eyes to turn towards each other or the inability to sustain convergence. It is the most common binocular anomaly. Approximately 6% of school-aged individuals suffer from convergence insufficiency.
Signs and Symptoms
Convergence insufficiency presents with prolong, visually demanding near tasks.
- Diplopia (double vision)
- Intermitted blurry vision
- Asthenopia (eye strain)
- Abnormal fatigue
- Decrease concentration
- Headaches
- Decrease comprehension
Cause
Convergence insufficiency is the inability for both eyes to point inwards at the same place and at the same time. It is caused by a dysfunction in eye focusing and movement skills which stem from poor spatial awareness.
Treatment
Convergence insufficiency is treated with vision therapy. Vision therapy or vision training is a type of physical therapy for the eyes. It is an effective non-surgical treatment for many visual problems. For convergence insufficiency, vision therapy is used to train eye focusing and movement skills.
The Convergence Insufficiency Treatment Trials was a 12 week study published in 2008 that included 221 children between the ages of 9 and 17. This national randomized trial tested the efficacy of vision therapy with in-office and home training in comparison to computer-based therapy, home therapy, and in-office placebo therapy. The study uncovered that 75% of indivdiuals who recieved in-office therapy by a trained therapist plus at home treatment reported fewer and less severe symptoms related to prolonged visually demanding near work.
Vision therapy is currently the only effective treatment for convergence insufficiency.