Optic

-al , op′tik, -al, adj. relating to sight, or to optics.— n. Op′tic ( Pope ), an organ of sight: an eye.— adv. Op′tically .— ns. Optic′ian , one skilled in optics: one who makes or sells optical instruments; Op′tics ( sing. ), the science of the nature and laws of vision and light; Optim′eter , Optom′eter , an instrument for measuring the refractive powers of the eye; Optom′etry , the measurement of the visual powers.— Optic axis , the axis of the eye—that is, a line going through the middle of the pupil and the centre of the eye. [Fr. optique —Gr. optikos .]