It is an imposing accomplishment of the visuomotor innervating system to continue deftly repositioning a pair of retinas so that single binocular vision is enjoyed while the eyes are scanning a distant scene. Yet, still more impressive is the ability to instantaneously shift the eyes from the distant scene to a wrist watch, identify the time, and immediately refixate the distant panorama. This feat of a swift, precise, coordinated change in the optics and alignment of the eyes which provides the finest detail of the near visual pattern to be sharply and singly seen is made possible by the near vision complex. The simultaneous application of many distinct phenomena during fixation at near makes up the near vision complex, the most important being (1) accommodation, (2) accommodative convergence, (3) fusional vergence, (4) fixation movement (version), and (5) pupillary constriction. This paper deals only with the first three components of
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