divergence
Divergence is a turning outward of the eyes, typically to keep fixation on an object as it moves away from the observer.1 Divergence is an example of a vergence eye movement.1
Divergence is an active process.2 Fusion holds when base-in prisms of increasing power are placed before the eyes, and the eyes then diverge beyond parallel visual axes.2 Electromyography shows increased activity in both lateral rectus muscles as a patient maintains fusion through base-in prisms.2
Smooth vergence is driven by near-response neurons in the supraoculomotor area of the midbrain reticular formation, which project directly to the oculomotor motoneurons.3 Some of these neurons are classed as convergence neurons and others as divergence neurons.3
More detail
Divergence was once described as a passive movement produced by relaxation of convergence and the elasticity of the orbital tissues.2 Electromyographic findings and the presence of fusional divergence show an active mechanism, although no divergence center has been located.2 In intermittent exotropia, lateral rectus activity rises before the medial rectus is inhibited, just before the eye diverges.2 Electrical stimulation of the frontal oculomotor area produces divergence in monkeys, which suggests a supranuclear control mechanism.2
Divergence excess is an exodeviation greater for distance than for near fixation, and divergence weakness is an esodeviation greater for distance than for near fixation.1
Sources (6)
- Pickwell's Binocular Vision Anomalies, Glossary
- von Noorden and Campos, Binocular Vision and Ocular Motility, ch. 22
- Adler's Physiology of the Eye, ch. 8
- Rutstein, R., Daum, K. (1997). Anomalies of Binocular Vision: Diagnosis & Management, Mosby.
- Alvarez, T. L., Vicci, V. R., Alkan, Y., Kim, E. H., Gohel, S., Barrett, A. M., ... & Zee, D. S. (2010). Vision therapy in adults with convergence insufficiency: clinical and functional magnetic resonance imaging measures. Optometry and Vision Science, 87(12), E985.
- Gamlin, P. D., & Yoon, K. (2000). An area for vergence eye movement in primate frontal cortex. Nature, 407(6807), 1003-1007.
Reviewed October 2026