||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. (b) See Moonblink.

&fist; Some writers (as Quain) use the word in the opposite sense, night blindness. See Hemeralopia.