hyperphoria
Hyperphoria is a latent upward deviation of one eye. The deviation becomes manifest on dissociation of the eyes and recovers once the dissociating factors are removed. A right hyperphoria is the same deviation as a left hypophoria, and the term hypophoria is not in general use.1
Primary hyperphoria is usually attributed to slight anatomical misalignment of the eyes, orbits or muscle insertions. Primary hyperphoria is usually less than 3 prism diopters and seldom causes symptoms. Hyperphoria can also be the early sign of a paretic elevator or depressor muscle, and a sudden onset of intermittent vertical diplopia with an incomitant deviation points that way. Superior oblique underaction is the most common cyclovertical incomitancy, and every hyperphoria therefore deserves a careful look for cyclophoria.1
Loss of place while reading is so characteristic of hyperphoria that a patient who skips lines should be presumed to have one until proven otherwise. Motion sickness, most often car sickness, is another symptom particular to hyperphoria.2
More detail
About 98% of symptom-free people show some hyperphoria after prolonged occlusion of one eye, and the hyperphoria disappears a few hours after binocular vision is restored. Vertical heterophoria has no link to the convergence system of the kind horizontal heterophoria has, which suggests anatomical factors play a larger part in its cause.1
Sources (5)
- Pickwell's Binocular Vision Anomalies, ch. 9
- Scheiman and Wick, Clinical Management of Binocular Vision, ch. 14
- Rutstein, R., Daum, K. (1997). Anomalies of Binocular Vision: Diagnosis & Management, Mosby.
- Caloroso, E.E., Rouse, M.W. (1993). Clinical Management of Strabismus.
- Butterworth-Heinemann. Scheiman, M., Wick, B. (2014). Clinical Management of Binocular Vision: Heterophoric, Accommodative, and Eye Movement Disorders. 4th ed., Lippincott Williams & Wilkins.
Reviewed October 2026