Pterygium: a geographical study.
D000328:Adult; D000368:Aged; D000375:Aging; D044466:Asian People; D001955:British Columbia; D004781:Environmental Exposure; D005007:Ethnology; D006801:Humans; D007194:India; D007198:Indians, North American; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology*; D011625:Pterygium / Q000453:epidemiology*; D013624:Taiwan; D013785:Thailand; D014466:Ultraviolet Rays; D044465:White People