dioptre

2 definitions found

dioptre - Collaborative International Dictionary of English v.0.48 :

  Dioptre \Di*op"tre\, n. [F. See 2d Dioptric.] (Optics)
     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.
     [1913 Webster]

dioptre - WordNet (r) 2.1 (2005) :

  dioptre
      n 1: 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 [syn: diopter,
           dioptre]