Nyctalopia
Nyctalopia (nik`tȧ*lō"pi*ȧ) , noun
[Latin nyctalopia, from nyctalops a nyctalops, Greek nykta`lwps. Greek nykta`lwps meant, a person affected either with day blindness or with night blindness, and in the former case was derived from ny`x, nykto`s, night + 'w`ps, 'wpo`s, the eye; in the latter, from ny`x + 'alao`s blind + 'w`ps.]
(a)
(Medicine) 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)
(Medicine) See Moonblink.
Some writers (as Quain) use the word in the opposite sense, night blindness. See Hemeralopia.