1. (n.) Cognizance by the senses or intellect\; apprehension by the bodily organs, or by the mind, of what is presented to them; discernment; apprehension; cognition.

2. (n.) The faculty of perceiving; the faculty, or peculiar part, of man's constitution by which he has knowledge through the medium or instrumentality of the bodily organs; the act of apprehending material objects or qualities through the senses; -- distinguished from conception.

3. (n.) The quality, state, or capability, of being affected by something external; sensation; sensibility.

4. (n.) An idea; a notion.

acuity acumen acuteness apperception appreciation appreciativeness apprehension astuteness awareness clear sight cogency cognition cognizance color vision comprehension conceit concept conception cone vision consciousness critical discernment day vision daylight vision discernment experience eye eye-mindedness eyesight fancy farseeingness farsight farsightedness feel feeling field of view field of vision flair foresight foresightedness grasp horizon idea image imago impression incisiveness insight instinct intellection intellectual object intuition judgment keen sight ken knowledge longheadedness longsightedness memory-trace mental image mental impression mindfulness night vision noesis note notice notion observation opinion penetration percept perceptiveness percipience peripheral field peripheral vision perspective perspicaciousness perspicacity perspicuity perspicuousness photopia power of sight providence purview quick sight range realization recept recognition reflection representation response response to stimuli rod vision sagaciousness sagacity scope scotopia seeing sensation sense sense impression sense of sight sense perception sensibility sensory experience sentiment sight sightedness supposition sweep theory thought trenchancy twilight vision understanding unobstructed vision view vision visual acuity visual field visual sense