Ocular convergence refers to the inward rotation of the eyes to maintain binocular fixation as objects approach closer to the viewer [1][2]. This allows the object’s image to fall on corresponding retinal regions in each eye to achieve unified vision [3]. The degree of convergence required depends on the object’s distance, with nearer objects eliciting greater convergence of the optical axes [4].

The neural mechanisms underlying ocular convergence involve premotor areas including the frontal eye fields and superior colliculus [5]. These areas integrate retinal disparity signals and coordinate innervation of the medial rectus eye muscles via cranial nerves III, IV, and VI to rotate the eyes inward [6]. Proprioceptive feedback from the extraocular muscles also provides an internal sense of eye position and convergence to premotor areas [4].

As part of the near triad, convergence is coupled to accommodation of the lens and pupillary constriction for unified near vision [3].

Sources:

1. Goldstein, E.B. & Stassen, W. (Eds.). (2020). Encyclopedia of psychology. Sage Publications.
2. Hatfield, G. (2002). Psychology, philosophy, and cognitive science: Reflections on the history and philosophy of experimental psychology. Mind & Language, 17(3), 207-232.
3. Rogers, K. (2007). The eye: The physiology of human perception. Britannica Educational Publishing.
4. Eysenck, M.W. & Keane, M.T. (2020). Cognitive psychology: A student’s handbook (8th ed.). Psychology Press.
5. Silbernagl, S. & Despopoulos, A. (1991). Color atlas of physiology. Thieme.
6. Eysenck, M.W. & Keane, M.T. (2020). Cognitive psychology: A student’s handbook (8th ed.). Psychology Press.