Optic
Pronunciation : Op"tic
Part of Speech : n.
Etymology : [From Optic, a.]
Definition : 1. The organ of sight; an eye. The difference is as great between The optics seeing, as the object seen. Pope.
2. An eyeglass. [Obs.] Herbert.
Source : Webster's Unabridged Dictionary, 1913
Pronunciation : Op"tic, Op"tic*al
Part of Speech : a.
Etymology : [F. optique, Gr. oculus eye. See Ocular, Eye, and cf. Canopy, Ophthalmia.]
Definition : 1. Of or pertaining to vision or sight. The moon, whose orb Through optic glass the Tuscan artist views. Milton.
2. Of or pertaining to the eye; ocular; as, the optic nerves (the first pair of cranial nerves) which are distributed to the retina. See Illust. of Brain, and Eye.
3. Relating to the science of optics; as, optical works. Optic angle (Opt.), the angle included between the optic axes of the two eyes when directed to the same point; -- sometimes called binocular parallax. -- Optic axis. (Opt.) (a) A line drawn through the center of the eye perpendicular to its anterior and posterior surfaces. In a normal eye it is in the direction of the optic axis that objects are most distinctly seen. (b) The line in a doubly refracting crystal, in the direction of which no double refraction occurs. A uniaxial crystal has one such line, a biaxial crystal has two. -- Optical circle (Opt.), a graduated circle used for the measurement of angles in optical experiments. -- Optical square, a surveyor's instrument with reflectors for laying off right angles.
Source : Webster's Unabridged Dictionary, 1913