from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Alternative spelling of diopter.
from the GNU version of the Collaborative International Dictionary of English
- n. A unit employed by oculists in numbering glasses according to the metric system; a refractive power equal to that of a glass whose principal focal distance is one meter.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a unit of measurement of the refractive power of a lens which is equal to the reciprocal of the focal length measured in meters; used by oculists
Sorry, no etymologies found.