Nyctalopia is a medical condition meaning poor night vision. Is there an equivalent single word meaning good night vision, either in medical or general parlance?
noun: the ability of the eye to adjust for night vision - Collins
This might not be quite what you're looking for because it is just the ability to see "normally" in the dark, but perhaps you could do something with it?
- the ability to see in reduced illumination (as in moonlight);
or night vision:
- is the ability to see in low light conditions. Whether by biological or technological means, night vision is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range. Humans have poor night vision compared to many animals, in part because the human eye lacks a tapetum lucidum.(Wikipedia)
also : night-eyed:
- Capable of seeing at night; sharp-eyed. "Your night-eyed Tiberius." --B. Jonson. [1913 Webster]
Increased night vision
(colloquial) A person with the medical condition Systemic lupus erythematosus, colloquially known as vampirism, with effects such as photosensitivity, brownish-red stained teeth, and increased night vision. (wiktionary)
Hemeralopia might be somewhat the word you are looking for:
a condition of the eyes in which the sufferer can see clearly at night but has impaired vision during the day; day blindness.
- belonging to or active during the night;
- of or relating to or occurring in the night;
This doesn't strictly mean good eye sight at night, but it could be implied depending on context.