title: Normal human tear pH by direct measurement.
abstract: Tear pH was measured in 44 normal subjects by immersing the lip of a microcombination glass pH probe in the tear fluid in the inferior cul-de-sac. The normal pH range was 6.5 to 7.6; the mean value was 7.0. This method provides a rapid and accurate measure of tear pH and may better our understanding of tear physiology and tear buffering capacity.
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008722:Methods; D008875:Middle Aged; D013666:Tears / Q000032:analysis*