The Niacin are a near-human species. They differed from Humans in that they lacked pupils or irises, instead bearing only empty sockets. In order to hide the fact they have no eye sockets, they wear bandages over their eyes or wear veils and visors. They possess a special form of telepathy that allows them to see where they are going and other people.
They were among the many species whose homes were destroyed by the Fen Domar. Some were taken to Earth while others were taken to earths colonies.