Op"tic (?), n. [From Optic, a.]

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.

 

© Webster 1913.


Op"tic (?), Op"tic*al (?), a. [F. optique, Gr. ; akin to sight, I have seen, I shall see, and to the two eyes, face, L. oculus eye. See Ocular, Eye, and cf. Canopy, Ophthalmia.]

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.

 

© Webster 1913.

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