The dynamics of fusional vergence eye movements in binocular dysfunction.

Two subject groups were designated as either normal or abnormal on the basis of their clinically determined vergence and heterophoria data. The question was asked, can these groups be differentiated on the basis of certain objectively measured dynamic properties of fusional vergence response? Vergence tracking rate, percentage completion of step responses, response velocity, and latency discriminated between the two experimenal groups; latency of convergence responses did not.