The use of litmus paper in the determination of the degree of tearing.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007765:Lacrimal Apparatus / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010209:Paper; D013666:Tears