Which term describes a tendency of one eye to deviate upward?

The term that accurately describes a tendency of one eye to deviate upward is “hyperphoria.” This condition refers specifically to a scenario where there is a latent vertical misalignment of the eyes, where one eye tends to drift upward relative to the other eye when not under visual control or when focusing on an object. Hyperphoria can occur due to muscle imbalance or other factors affecting eye coordination.

In selecting this correct term, it is essential to differentiate it from similarly sounding conditions. Hypotropia describes a condition where one eye is physically positioned lower than the other eye, rather than the tendency to deviate upward. Esophoria involves a tendency for one eye to turn inward (convergence), while exophoria refers to the tendency for one eye to turn outward (divergence). Understanding these distinctions helps clarify why "hyperphoria" is the appropriate term for upward deviation.