DIOPTRIC (2)

{ Di‐op″tric (?), Di‐op″tric‐al (?), } a. [[Gr. � belonging to the use of the �; � = διά through + the root of � I shall see: cf. F. dioptrique.]] Of or pertaining to dioptrics; assisting vision by means of the refraction of light; refractive; as, the dioptric system; a dioptric glass or telescope. “Dioptrical principles.” Nichol. Dioptric curve (Geom.), a Cartesian oval. See under Cartesian.