catflap.org Online Dictionary Query

  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.
                                                    --Milton.
          [1913 Webster]
  
     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]
        [1913 Webster]
  
     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
            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.
        [1913 Webster]

  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.