nyctalopia

Definitions

  • WordNet 3.6
    • n nyctalopia inability to see clearly in dim light; due to a deficiency of vitamin A or to a retinal disorder
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Webster's Revised Unabridged Dictionary
    • n Nyctalopia nĭk`tȧ*lō"pĭ*ȧ (Med) A disease of the eye, in consequence of which the patient can see well in a faint light or at twilight, but is unable to see during the day or in a strong light; day blindness.☞ Some writers (as Quain) use the word in the opposite sense, night blindness. See Hemeralopia.
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Century Dictionary and Cyclopedia
    • n nyctalopia Night-blindness.
    • n nyctalopia Day-blindness.
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Chambers's Twentieth Century Dictionary
    • n Nyctalopia nik-ta-lō′pi-a the defective vision of persons who can see in a faint light but not in bright daylight: sometimes applied to the opposite defect, inability to see save in a strong daylight—also Nyc′talopy
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Etymology

Webster's Revised Unabridged Dictionary
L. nyctalopia, fr. nyctalops, a nyctalops, Gr. nykta`lwps. Gr. nykta`lwps meant, a person affected either with day blindness or with night blindness, and in the former case was derived fr. ny`x nykto`s, night + 'w`ps 'wpo`s, the eye; in the latter, fr. ny`x + 'alao`s blind + 'w`ps
Chambers's Twentieth Century Dictionary
Gr. nyktalōps, seeing by night only—nyx, nyktos, night, ōps, vision.