Letter: Blindness in the nine states of Norteast Brazil.
D001766:Blindness / Q000453:epidemiology / Q000209:etiology*; D001938:Brazil; D002664:Child Nutritional Physiological Phenomena; D002675:Child, Preschool; D006801:Humans; D009749:Nutrition Surveys; D014802:Vitamin A Deficiency / Q000150:complications*