vision

(vish’un) [L. tis‘ie, tid’ere to see]. 1. The act or faculty of seeing: sight. 2. An apparition; a subjective appearance as of something seen which does not really exist. 3. Visual acuity: symbol, Vv. ac tic v., vision marked by complete lo of the color sense; total color-blindne . binocular v., the use of both eyes together without diplopia. central v., that which is performed by the macula lutea. Called also direct vr. chromatic v. Same as chroma lops i a. defective v., depraved v. Same as dysopia. direct v. Sze central υ. double v. Same as diplopia. facial v., the power of judging of the distance, direction, etc., of objects by the sensation felt in the skin of the face. -v. Same as hemianopia. halo v. See iridescent v. indirect v., peripheral v., that which is performed by the parts of the retina outside of the macula lutea. i descent v., vision in which a definite ring is seen surrounding artificial lights, which thus become invested with a colored halo. Called also halo v. multiple v. Same as polyopia. v. nul, the existence of scotomas in the field of vision of which the patient is not aware. v. obscure, the existence of scotomas in the field of vision of which the patient is conscious. pseudoscopic v., the reverse of stereoscopic vision: vision in which the object appears not as a solid body, but as a hollow one. rainbow v. Same as iridescent v. solid v., stereoscopic v., perception of the relief of objects or of their depth; that in which objects seen appear as solid objects, and not as flat pictures. word-v., the special function of the general visual center.