It has been reported that diabetics are more likely to develop tear film dysfunction compared to non-diabetics. Even so, there has been very little research reported on the correlation between blood glucose level and quality of tears. Objective: The purpose of the study was to investigate the influence of blood glucose level on TBUT among young adults with diabetes. Methods: A cross-sectional study consisting of 37 diabetic patients within the age range of 19-39 years was carried out at International Islamic University Malaysia (IIUM) Optometry Clinic, Kuantan, Pahang, Malaysia. The subjects were tested for random blood glucose level (RBS) and undergone tear
break up time (TBUT) test. Nonparametric test was used namely Spearman correlation to determine the association between RBS and TBUT. Results: TBUT median (interquartile range) value was 7.5 (11.55) seconds. Meanwhile, the negative association was found between (RBS) and TBUT in diabetics (r = -0.126). However, the correlation was not statistically significant (p>0.05). Tear film break up time was not associated with the random blood glucose level. Conclusion: Tear film break up time seems to be not affected by blood glucose level.