1. The act of leading, bringing, conducting. 2. In ophthalmology, ocular rotations with reference to one eye; usually additionally designating direction of movement of the eye; e.g., rotation toward the nose, adduction; toward the temple, abduction; upward, supra- or sursumduction; downward, deorsumduction; of the upper pole of one cornea, cycloduction; of the upper pole of one cornea outward, excycloduction; of the upper pole of one cornea inward, incycloduction. [L. duco, to lead]
- forced d. a maneuver to determine whether a mechanical obstruction is present in the eye; with forceps grasping an eye muscle, an attempt is made to passively move the eyeball in the direction of restricted rotation. SYN: passive d..
- passive d. SYN: forced d..
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duc·tion 'dək-shən n a turning or rotational movement of the eye
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duc·tion (dukґshən) [L. ductio, from ducere to lead] in ophthalmology, the rotation of an eye by the extraocular muscles around its horizontal, vertical, or anteroposterior axis, the direction of the movement of the eye being indicated by prefixes. See infraduction, supraduction, abduction, adduction, and cycloduction, and see also vergence (def. 2) and version (def. 5).Medical dictionary. 2011.