**5. Conclusions**

In conclusion, SM is inexpensive, quick and easy to perform, and may be a suitable tool for epidemiology studies. Although associated with dry eye symptoms, this test is not equivalent to any one of the conventional tests, but still related to some aspect of tear function. It should be explored in other populations.

**Author Contributions:** Data collection, M.A.K.M.R. and S.M.; methodology, M.A.K.M.R., S.M. and L.T.; conceptualization, L.T.; formal analysis, Z.Z.T., C.H.Y.T. and L.T.; writing—original draft preparation, Z.Z.T., C.H.Y.T. and L.T.; writing—review and editing, Z.Z.T., L.T. and H.S.O.; supervision, L.T.; All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by National Medical Research Council, gran<sup>t</sup> number NMRC\CSA\017\2017"

**Acknowledgments:** Funding advisory board or gifts from Santen, Alcon-Novartis, Allergan, B & L, LFAsia, Bioessex, Eye-lens, Dyamed, ZAS Ophthalmic, Bangladesh.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
