Heterophoria

What it means

Heterophorias are latent deviations that are controlled by fusion. In certain circumstances (specific visual tasks, fatigue, illness, etc.), fusion can no longer be maintained and decompensation occurs.

In contrast to heterophoria, heterotropias are manifest deviations. Some individuals may be phoric in one situation (e.g. for distance) and tropic in another (e.g. for near). The distinction between heterotropia and heterophoria is that heterotropia refers to a misalignment of the eyes when the affected individual is looking at an object while the eyes are uncovered whereas heterophoria is a misalignment that is observed only when the two eyes are no longer looking at the same object. The monocular cover-uncover test is the most important test for detecting the presence of manifest strabismus and for differentiating a heterophoria from a heterotropia.

Part of the broader category