Disparity vergence: a proposed name for a dominant component of binocular vergence eye movements

A proposal to name the dominant aspect of vergence "disparity vergence" is put forward. Support for this proposal is gathered by briefly reviewing the components of vergence: (1) disparity vergence, the visual feedback control system for removing binocular disparity with an appropriate binocular convergence or divergence, (2) accommodative vergence, a synkinesis with accommodative motor control, (3) proximal vergence, and (4) tonic vergence. Sensory fusion is a higher level perceptual process aided by disparity vergence, and historically the term fusional vergence called attention to this relationship. However, it now appears to obscure the fact that disparity is the only direct stimulus to vergence.