See night blindness.
[Late Latin nyctalōpia, from Greek nuktalōps, night-blind : nux, nukt-, night; see nekw-t- in the Appendix of Indo-European roots + alaos, blind + ōps, ōp-, eye; see okw- in the Appendix of Indo-European roots.]
nyc′ta·lopic (-lōpĭk, -lŏpĭk) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.