4. Tear Strip Meniscometry (SMTube) Remove SMTube from the sterile pouch. Hold the centre of SMTube. Do not touch the dye area. Immerse the tip of the SMTube to the lateral lower lid tear meniscus of an eye for 5 seconds. Take extra precaution to prevent the tip from touching the patients' conjunctiva. After 5 seconds, remove the SMTube from the lower lid tear meniscus. Measure the length of the column stained blue in colour.