<unk>  determines whether the eye produces enough tears to keep it moist. This<unk>  is used when a person experiences very dry eyes or excessive watering of the eyes. It poses no risk to the subject. A negative (more than 10 mm of moisture on the filter paper in 5 minutes)<unk>  result is normal. Both eyes normally secrete the same amount of tears. It is named for Otto<unk> .
Schirmer's test
Allen's test
Schiller's test
Tzanck test
Ober's test
Jobe's test
Heidelberg test
Heaf test