- The act of seeing. SEE ALSO: sight. [L. visio, fr. video, pp. visus, to see]- direct v. SYN: central v..- double v. SYN: diplopia.- facial v. sensing the proximity of objects by the nerves of the face, presumed in the case of the blind and also in sighted persons who are blindfolded or in darkness.- indirect v. SYN: peripheral v..- multiple v. SYN: polyopia.- night v. SYN: scotopic v..- oscillating v. SYN: oscillopsia.- photopic v. v. when the eye is light-adapted. See light adaptation, light-adapted eye. SYN: cone v., photopia.- red v. SYN: erythropsia.- rod v. SYN: scotopic v..- scotopic v. v. when the eye is dark-adapted. SEE ALSO: dark adaptation, dark-adapted eye. SYN: night v., rod v., scotopia, twilight v..- stereoscopic v. the single perception of a slightly different image from each eye. SYN: stereopsis.- tinted v. SYN: chromatopsia.- triple v. SYN: triplopia.- tubular v. a constriction of the visual field, as though one were looking through a hollow cylinder or tube. SYN: tunnel v..
* * *vi·sion 'vizh-ən n1) the act or power of seeing: sight2) the special sense by which the qualities of an object (as color, luminosity, shape, and size) constituting its appearance are perceived through a process in which light rays entering the eye are transformed by the retina into electrical signals that are transmitted to the brain via the optic nerve
* * *vi·sion (vizhґən) [L. visio, from vidēre to see] 1. the special sense by which objects in the external environment are perceived by means of light they give off or reflect, which stimulates the photoreceptors in the retina; called also sight. 2. the act of seeing. 3. an apparition; a subjective sensation of vision not elicited by actual visual stimuli. 4. visual acuity.
Medical dictionary. 2011.