Nyc`ta*lo"pi*a (?), n. [L. nyctalopia, fr. nyctalops a nyctalops, Gr. . Gr. meant, a person affected either with day blindness or with night blindness, and in the former case was derived fr. , , night + , , the eye; in the latter, fr. + blind + .] Med. (a)
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.
© Webster 1913.