Ficarra AP, Berman JB, Rosenfield M, Portello JK.

Vision training: predictive factors for success in visual therapy for patients with convergence excess.

J Optom Vision Dev 27 (4): 213-219, 1996.

A retrospective study was conducted of 31 patients who had received vision therapy for convergence excess. The mean number of training sessions was 19. Vision therapy produced a significant reduction in symptoms of both distance blur and headaches. Prior to treatment, 55% of the patients experienced headaches related to near work; following therapy only 2 patients reported headaches. Before receiving vision therapy, 41% of the patients reported transient visual blur; after therapy only 3 patients still reported experiencing this symptom.