Conservation of substance in the blind and partially sighted.
D000293:Adolescent; D001766:Blindness; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D003071:Cognition; D003210:Concept Formation; D004519:Education, Special; D006801:Humans; D007600:Judgment; D013647:Task Performance and Analysis; D014110:Touch; D014785:Vision, Ocular; D014796:Visual Perception