Congenital stationary night blindness: An inherited eye disorder that is not progressive ("stationary") and principally affects the rod photoreceptors in the retina, impairing night vision. There may also be moderate to high myopia (short sightedness). Under good lighting conditions, there is usually no visual deficit. The disorder is diagnosed by electroretinography. There are several different types of the disorder which are inherited in an autosomal dominant, autosomal recessive, or X-linked recessive manner. The X-linked type affects almost exclusively males and accounts for the predominance of males with congenital stationary night blindness. Children with the disorder may have a fear of the dark.