Vergence adaptation in esotropia

Vergence adaptation and anomalous fusional movements have been used by strabismics to overcome prism. There has been controversy in the literature regarding the nature of the vergence responses by esotropes to prism, i.e., fusional, avoidance of fusion, and/or anomalous fusion. This paper reviews the various types of movements made by esotropes to prism and attempts to explain the mechanism. In addition, the relation of these vergence movements to prismatic, orthoptic, and surgical correction is discussed.