Noun | 1. | ![]() visual system - the sensory system for vision exteroception - sensitivity to stimuli originating outside of the body stigmatism - normal eyesight achromatic vision - vision using the rods acuity, sharp-sightedness, visual acuity - sharpness of vision; the visual ability to resolve fine detail (usually measured by a Snellen chart) binocular vision - vision involving the use of both eyes central vision - vision using the fovea and parafovea; the middle part of the visual field distance vision - vision for objects that a 20 feet or more from the viewer monocular vision - vision with only one eye near vision - vision for objects 2 feet or closer to the viewer night vision, night-sight, scotopic vision, twilight vision - the ability to see in reduced illumination (as in moonlight) daylight vision, photopic vision - normal vision in daylight; vision with sufficient illumination that the cones are active and hue is perceived peripheral vision - vision at the edges of the visual field using only the periphery of the retina |