title: Symposium on visual disability. Introduction.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001766:Blindness / Q000453:epidemiology* / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D004739:England; D006801:Humans; D008875:Middle Aged; D012042:Registries; D014852:Wales