Hold the centre of SM Tube, Do not touch the dry area

Immerse a tip of the SMTube into the tear me- niscus in lateral lower lid for 5 seconds. Take extra care so that the SMTube would not touch the patients' cornea nor the conjunctiva

in 5 seconds, read the tear absorbing length and mark it by an oil-based pen.

Repeat  the test for the other  eye.

Measure the length of the column stained by blue colour.