There has been substantial progress in our understanding of the ocular surface system/lacrimal function unit in the past 15 years. Keratoconjunctivitis sicca, more commonly referred to as dry eye syndrome (DES), is the most frequently encountered condition and diabetes mellitus (DM) has been identified as one of the leading causes of DES. Poor glycemic control affects both the anterior and the posterior segments of the eye and increasing prevalence of diabetes-associated DES (DMDES) has been reported in recent years. The pathogenesis and specific features of DMDES remain uncertain and interventions are limited to those used in DES. This review outlines the pathogenesis, clinical manifestations, and the current preventive and treatment strategies for diabetes-related DES.