The effect of orthoptic treatment upon the vergence adaptation mechanism.

This paper is a review of the research work that has been carried out over the past few years investigating the ability of the oculomotor system to adapt to prism-induced heterophoria. Our results show that subjects with normal binocular vision can adapt to horizontal and vertical prism-induced heterophorias whether fixating at distance or near. Further studies have shown that subjects with symptomatic abnormal binocular vision have an abnormal adaptation mechanism. Finally, we have found that when orthoptic treatment results in relief from the symptoms, there is an associated improvement in the subjects' ability to adapt to prism-induced heterophoria.