proximal convergence
Proximal convergence is convergence driven by the awareness that an object is near. Synonyms include psychic convergence and voluntary convergence.1 Proximal convergence is one of the four components of reflex convergence, along with tonic, accommodative and fusional convergence.2
Proximal vergence contributes up to 70% of the vergence demand for near tasks, and its peak velocity is substantially faster than that of disparity vergence.3 Proximal vergence can start the near response when disparity cues are unavailable, as when a near object is seen by only one eye or its images fall far in the peripheral retina.3 Proximity is the most powerful of the three main cues that drive convergence at near, ahead of disparity and accommodation.4
More detail
Peak velocities measured for proximal convergence and divergence are 66 and 39 degrees per second, against 14 and 10 degrees per second for disparity vergence.3 Proximal vergence can be estimated clinically by measuring the heterophoria with the von Graefe technique through pinholes, with targets at 2.0, 1.0, 0.5 and 0.25 m. The pinholes remove accommodative vergence and the von Graefe dissociation removes disparity vergence, so the change in angle across the distances estimates the proximal component.3
The size of the proximal cue varies between individuals. Excessive proximal convergence is a likely cause of a convergence excess esophoria that no other finding explains.4
Sources (9)
- AOA Clinical Practice Guideline, Care of the Patient with Accommodative and Vergence Dysfunction, glossary
- von Noorden and Campos, Binocular Vision and Ocular Motility, ch. 5
- Scheiman and Wick, Clinical Management of Binocular Vision, ch. 16
- Pickwell's Binocular Vision Anomalies, ch. 7
- Caloroso, E.E. and Rouse, M.W. (1993) Clinical management of strabismus. Boston: Butterworth-Heinemann.
- Charman, W.N. (2008) 'The eye in focus: accommodation and presbyopia', Clinical and Experimental Optometry, 91(3), pp. 207–225.
- Noorden, G.K. von and Campos, E.C. (2002) Binocular Vision and Ocular Motility: Theory and Management of Strabismus. 6th edn. St. Louis: Mosby.
- Rowe, F.J. (2012) Clinical Orthoptics. 3rd edn. Chichester, West Sussex: Wiley-Blackwell.
- Scheiman, M. and Wick, B. (2020) Clinical management of binocular vision: heterophoric, accommodative, and eye movement disorders. 5th edn. Philadelphia: Wolters Kluwer.
Reviewed October 2026