资料来源 : Webster's Revised Unabridged Dictionary (1913)

Optic \Op"tic\, Optical \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.