nycti-, nyct-, nycto-, nyc- +
(Greek: night; a relationship to darkness, dark)
This word is frequently spelled "nycthemeron". It was written as such because in classical times a new day started at sunset, a rule continued in some religions today. Although nychthemeron is generally unknown, it is still used by some people, as well as its adjective, "nychthemeral".
Those scientists who study the ways in which the body's physiological activity varies hour by hour, as in sleep research, make a distinction between nychthemeral and the more common Latin-derived circadian which comes from circa, "round, around" + dies, "day".
Circadian refers to daily cycles that are driven by an internal body clock, while nychthemeral rhythms are the result of the external environment.
Smoking tobacco may impair the ability to see at night. Hypoxia associated with being above sea level in an aircraft will also decrease night vision.2. The inability to see well under scotopic (dark) conditions, due to faulty rod function.
The “rod” used here refers to any of the photoreceptor cells of the retina serving scotopic vision. “Scotopic vision” designates the dark-adapted state of vision, in which color perception is replaced by shades of black and white. It is served by the rod photorecptors.
3. A condition of the eyes in which the person can see well during the day, in a strong light, or on bright days, but see poorly at night, in a faint light, or on dull or dark days; night blindness; day sight.
4. The opposite of nyctalopia is hermeralopia, or day blindness.
2. Orientation movements of plants during the night.
Nastic movements of plant organs in response to the changes in light and temperature that occur between day and night (and vice versa). Examples are the opening and closing of many flowers and the folding together of the leaflets of clover and other plants at night.
Bathypelagic refers to creatures that live in deep water below the level of light penetration, between 1,000 meters and 4,000 meters deep.