The Collaborative International Dictionary of English v.0.48:
Optic \Op"tic\ ([o^]p"t[i^]k), Optical \Op"tic*al\
([o^]p"t[i^]*kal), a. [F. optique, Gr. 'optiko`s; akin to
'o`psis sight, 'o`pwpa I have seen, 'o`psomai I shall see,
and to 'o`sse the two eyes, 'o`ps face, L. oculus eye. See
Ocular, Eye, and cf. Canopy, Ophthalmia.]
1. Of, pertaining to, or using vision or sight; as, optical
illusions. [WordNet sense 2]
Syn: ocular, optic, visual.
[1913 Webster + WordNet 1.5]
The moon, whose orb
Through optic glass the Tuscan artist views.
2. Of or pertaining to the eye; ocular; as, the optic nerves
(the first pair of cranial nerves) which are distributed
to the retina; the optic (or optical) axis of the eye. See
Illust. of Brain, and Eye. [WordNet sense 3]
3. Relating to the science of optics or to devices designed
to assist vision; as, optical works; optical equipment.
[WordNet sense 1]
[1913 Webster +PJC]
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
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.