DIOPTRIC, DIOPTRICAL adjective [Gr., to see through; to see.] 1. Affording a medium for the sight; assisting the sight in the view of distant objects; as a dioptric glass. 2. Pertaining to dioptrics, or the science of refracted light.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI