See Also: optic(dictionary)
optic cup(medicine)
optic(dictionary)
Cup, optic(health)
optic pit(medicine)
Optic(medicine)
Optic nerves(health)
optic placodes(medicine)
optic papilla(medicine)
optic neuroma(medicine)

optic (iou)



optic adjective & noun. LME.
[Old & mod. French optique or medieval Latin opticus from Greek optikos, from optos seen, visible: see -IC.]
A. adjective.
1. Now chiefly Anatomy & Medicine. Of, pertaining to, or connected with the eyes, the faculty of sight, or the process of vision; of or pertaining to light, esp. as the medium of vision. LME.
2. Of, pertaining to, or skilled in optics (see sense B.1 below). M16-E18.
3. = OPTICAL adjective 3. arch. E17.
Special collocations: optic angle (a) = visual angle s.v. VISUAL adjective; (b) the angle between the optic axes of the eyes when directed to the same object; (c) the angle between the optic axes of a biaxial doubly-refracting crystal. optic axis (a) the straight line through the centres of the pupil and the crystalline lens, the axis of the eye; the axis of a lens; (b) a line in a doubly-refracting crystal such that a ray of light passing in the direction of it suffers no double refraction. optic chiasma: see CHIASMA 1. optic commissure the optic chiasma. optic cup Embryology a cuplike depression in the front of the optic vesicle of the embryo which eventually forms the retina. optic disc the raised disc on the retina at the point of entry of the optic nerve, lacking visual receptors and so forming a blind spot. optic lobe Anatomy each of two or (in mammals) four lobes of the dorsal part of the midbrain from which in part the optic nerves arise. optic measure a device fastened to the neck of an inverted bottle for measuring out spirits etc. (cf. sense B.4 below). optic nerve either of the second pair of cranial nerves, which supply the retinas, esp. that part of either between the optic chiasma and the eye. optic neuritis Medicine inflammation of an optic nerve. optic papilla = optic disc above. optic pencil: see PENCIL noun. optic tectum: see TECTUM 2. optic thalamus Anatomy either of two lateral geniculate bodies which relay visual information from the optic tract. optic tract the pathway between the optic chiasma and the brain. optic vesicle a vesicle connected with the forebrain of the embryo, from which the optic nerve and retina are developed.
B. noun.
1. In pl. (now treated as sing.) & sing. The branch of physics that deals with the properties and phenomena of light. M16.
physical optics: see PHYSICAL adjective.
2. The eye. Usu. in pl. Now joc. E17.
b. In pl. Visual power. M17-E18.
3. a. An eyeglass, a magnifying glass; a microscope, a telescope, a photographic lens. Now rare. E17.
b. In pl. The optical components of an instrument or apparatus. M20.
4. (Usu. Optic). (Proprietary name for) an optic measure. E20.
opticity noun (in the brewing and food industries) the degree of optical activity of carbohydrates in a solution, as a measure of concentration E20.