Changing vergence function in persons with Parkinson's disease and convergence insufficiency

Individuals with Parkinson's disease and convergence insufficiency were assigned vergence training. After two months, average positive fusional vergence increased and average near point of convergence decreased. Vergence can be improved with training in persons with Parkinson's disease who also have convergence insufficiency. •Convergence insufficiency (CI) causes visual symptoms and is more common in people with Parkinson's disease (PD).•People with CI and PD were given two months of home-based vergence training.•Near point of convergence decreased and positive fusional vergence increased in persons with PD who completed training.•The data support further investigation of vergence training as therapy for CI in PD.