SHORT-SIGHTEDNESS, n. 1. A defect in vision, consisting in the inability to see things at a distance, or at the distance to which sight normally extends. Short-sightedness is owing to the too great convexity of the crystaline humor of the eye, by which the rays of light are brought to a focus too soon, that is, before they reach the retina. 2. Defected or limited intellectual sight; inability to see far into futurity or into things deep or abstruse.