light, <perceptual> noun
characteristic of all sensations and perceptions that is specific to the visual system
Note 1 to entry: Light is normally, but not always, perceived as a result of the action of a light stimulus on the visual system.
Note 2 to entry: This entry was numbered 845-02-17 in IEC 60050-845:1987.
Note 3 to entry: This entry was numbered 17-659 (1.) in CIE S 017:2011.