| axis cylinder | An obsolete term for axon. (05 Mar 2000) |
|---|---|
| concave | Having a depressed or hollowed surface. Origin: L. Concavus, arched or vaulted (05 Mar 2000) |
| concave lens | A diverging minus power lens. Synonym: minus lens. (05 Mar 2000) |
| concave mirror | A spherical reflecting surface that constitutes a segment of the interior of a sphere. (05 Mar 2000) |
| cylinder | 1. A cylindrical lens. 2. A cylindrical or rodlike renal cast. 3. A cylindrical metal container for gases stored under high pressure. Origin: G. Kylindros, a roll (05 Mar 2000) |
| cylinder retinoscopy | Determination of spherical, astigmatic, and refractive error using cylindrical lenses. (05 Mar 2000) |
| double concave lens | A lens that is concave on two opposing surfaces. Synonym: concavoconcave lens, double concave lens. (05 Mar 2000) |
| Kulz's cylinder | A renal cast of strongly refracting granules said to be indicative of imminent coma in diabetes. Synonym: Kulz's cylinder. (05 Mar 2000) |