title: Astigmatism as a congenital, bilateral and symmetrical entity (observations based on the study of 51,000 patients).
mesh_terms: D000221:Adaptation, Ocular; D000293:Adolescent; D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000151:congenital / Q000235:genetics / Q000503:physiopathology*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014796:Visual Perception / Q000502:physiology