Name given to human beings who can see in the dark. They are extremely rare. For example, a Dr. Tentin of Paris reported in 1874 the case of Marie Verdun, a girl of 18:
"Although her eyes do not present any special morbid character she is forced to keep her eyelids closed during the day, and to cover her head with a thick veil. On the other hand, when the shutters of the room are hermetically fastened, she reads and writes perfectly in the deepest darkness." Auguste Müller, the Stuttgart somnambulist, saw perfectly well and recognized all persons and objects in the greatest darkness.
In view of the remarkable precision with which objects move in the darkness of the séance room, it was suggested that some mediums might be nictalopes. As, however, the same precision has been observed when the medium goes into trance, the theory as a normal explanation seems untenable.
(See also eyeless sight )