Dry eye is a multi-factorial disease that is frequently encountered in ophthalmological practice. Common dry eye symptoms include eye irritation, heaviness of the eyelids, blurred vision and light sensitivity (1). The worldwide prevalence of dry eye is generally high (2-4). In Asia, dry eye may affect up to 22% of adults above 40 years in China (5) and Japan (3). In Asian patients older than 65 years, prevalence rates of dry eye can be as high as 80% if diagnosis is based on abnormal tear stability, or as high as 60% on meibomian gland dysfunction (MGD), a major cause of tear instability (6).