Adaptation to Lens‐Induced Heterophorias

In previous studies we have shown that subjects with normal binocular vision adapt to prism‐induced heterophorias. In this study we have continued the work by investigating whether the oculomotor system can also adapt to lens‐inuced heterophorias. It was found that subjects gradually adapted to the esophoria induced when viewing a distance chart through negative lenses. Adaptation also occurred to lens‐induced esophoria and exophoria at near, while at distance, where the visual feedback was unaltered, the phoria remained virtually constant. These findings demonstrate the flexibility of the oculomotor system.