• synonyms


noun Ophthalmology.
  1. night blindness.
  2. hemeralopia.
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Origin of nyctalopia

1675–85; < Late Latin nyctalōpia < Greek nykt- nyct- + al(aós) blind + -ōpia -opia
Related formsnyc·ta·lop·ic [nik-tl-op-ik] /ˌnɪk tlˈɒp ɪk/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for nyctalopia

Historical Examples of nyctalopia

  • Government, offer to it, to discover the remedy for nyctalopia, 335.

    An Account of Timbuctoo and Housa Territories in the Interior of Africa

    Abd Salam Shabeeny

  • Nyctalopia, so frequently encountered, must be regarded as a circulatory symptom rather than as one of nervous origin.

    Scurvy Past and Present

    Alfred Fabian Hess

  • His nyctalopia was a great advantage, his cat-like sight enabling him to distinguish the smallest object in the deepest gloom.

British Dictionary definitions for nyctalopia


  1. inability to see normally in dim lightNontechnical name: night blindness Compare hemeralopia
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Word Origin for nyctalopia

C17: via Late Latin from Greek nuktálōps, from nux night + alaos blind + ōps eye
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

nyctalopia in Medicine


  1. A condition of the eyes in which vision is normal in daylight or other strong light but is abnormally weak or completely lost at night or in dim light and that results from vitamin A deficiency, disease, or hereditary factors.night blindness
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Related formsnyc′ta•lopic (-lōpĭk, -lŏpĭk) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.