divergence excess
An outward deviation of the eyes that is much larger at distance than at near. The distance exodeviation exceeds the near deviation by at least 10 prism diopters, the near exophoria is small and well compensated, and the distance deviation may break down into an intermittent exotropia1,2.
Tonic vergence is low, so the eyes drift outward when nothing near holds them, while accommodative convergence pulls them in again when the patient reads3. In true divergence excess, the measured AC/A ratio is usually normal, and the near angle stays small even after an hour of occlusion3,4.
More detail
Simulated divergence excess is the commoner form, in which an hour of patching relaxes fusional convergence, and the near angle grows until it matches the distance angle; the patient actually has a basic exotropia hidden by convergence at near1. It is also distinct from convergence insufficiency, in which the exodeviation is larger at near, and the two do not cause one another1.
The typical patient is a teenager, more often female, whose eye drifts out in bright light or when tired. Suppression usually replaces diplopia at distance, there is no amblyopia, and stereopsis at near is normal3,4.
Sources (7)
- von Noorden and Campos, Binocular Vision and Ocular Motility, ch. 17, Exodeviations
- AOA, Care of the Patient with Accommodative and Vergence Dysfunction
- Scheiman and Wick, Clinical Management of Binocular Vision, ch. 2 and ch. 10
- Pickwell's Binocular Vision Anomalies, ch. 8, Exophoric Conditions
- Rutstein, R., Daum, K. (1997). Anomalies of Binocular Vision: Diagnosis & Management, Mosby.
- Rouse, M. W., Hyman, L., Hussein, M., & Pollard, H. (1998). Use of binocular crossed cylinders in the management of divergence excess. Ophthalmic and Physiological Optics, 18(6), 528-538.
- Mohney, B. G., & Diehl, N. N. (2008). Incidence and management of true and simulated divergence excess in a population-based cohort of young children. American journal of ophthalmology, 145(6), 1070-1073.
Reviewed October 2026