Graphical analysis of prism adaptation, convergence accommodation, and accommodative convergence.

A new form of graphical case analysis is described which quantifies static interactions between accommodative convergence, convergence accommodation, and prism adaptation. A clinical gradient measure of the CA/C ratio is compared to haploscopic measures to demonstrate the validity of the new clinical technique for measuring convergence accommodation. Graphical and computational methods are illustrated which predict the quantitative interactions between accommodation and convergence that occur after the phoria is partially corrected by lenses or prisms. Complete correction of convergence accommodation errors with spherical lenses or elimination of the stimulus to convergence accommodation by full correction of the associated phoria with prism will simplify the correction of binocular disorders by preventing the complex interactions of accommodative convergence with convergence accommodation. The new form of graphical analysis quantifies the predicted stress upon binocular vision induced by convergence accommodation.