ocular

Etymology

Derived from the Latin oculāris (“of the eye”), from oculus (“eye”).

adj

1. Of, or relating to the eye, or the sense of sight
   The medication may have adverse ocular side effects.
   It took some time after he lost his eye for him to receive his ocular prosthesis.
   The eyes of men converse as much as their tongues, with the advantage, that the ocular dialect needs no dictionary, but is understood all the world over. 1860, Ralph Waldo Emerson, “Behavior”, in The Conduct of Life, Boston: Ticknor & Fields, page 156
2. Resembling the eye.
   ocular markings on the wings of a butterfly
3. Seen by, or seeing with, the eye; visual.
   For as Thomas was an ocular Witness of Christ’s Death and Burial, so were the other Disciples of his Resurrection; having actually seen him after he was risen. 1692, Robert South, “A Discourse concerning Our Saviour’s Resurrection”, in Sermons Preached upon Several Occasions, 6th edition, volume V, London: Jonah Bowyer, page 171
   Captain Lincoln proceeded to relate some of the strange fables and fantasies, which, as it was impossible to refute them by ocular demonstration, had grown to be articles of popular belief, in reference to this old picture. 1842, Nathaniel Hawthorne, “Edward Randolph’s Portrait”, in Twice-Told Tales, volume 2, Boston: James Munroe, page 32
   Suddenly starting from a proposition, exactly and sharply defined, in terms of utmost simplicity and clearness, he rejected the forms of customary logic, and by a crystalline process of accretion, built up his ocular demonstrations in forms of gloomiest and ghastliest grandeur, […] October 20, 1849, Nathaniel Parker Willis, “Death of Edgar Poe”, in Home Journal

noun

1. The eyepiece of a microscope or other optical instrument.
2. Any of the scales forming the margin of a reptile's eye.