Effect of vision training on patients who fail Sheard's criterion.

One hundred convergence insufficiency patients who did not meet Sheard's criterion at near were given a program of in-office and at-home training. The objective was to see if they would meet Sheard's criterion after training. Results were analyzed in terms of the numbers successfully meeting this criterion as well as other criteria, i.e. Percival's, elimination of symptoms, improvement of stereopsis, and elimination of fixation disparity. Of the 100 patients, 84 successfully met Sheard's criterion after therapy. Failure to meet Sheard's criterion correlated well with having subjective symptoms.