Blepharitis can be a significant source of discomfort, and accounts for a good number of office visits. Dr. Davidson discusses diagnostic tools such as the TearLab Osmolarity system, Sjö, InflammaDry, LipiView, and LipiView II that can help one differentiate between the different causes of ocular surface disease. Each tool has proprietary mechanisms for identifying significant contributors, either through meibomian gland imaging, detection of inflammatory markers in the tear film, or measuring tear film osmolarity. Although these tools can be helpful in the diagnosis and management of ocular surface disease, they do not take the place of a careful history and physical examination, but can be helpful for monitoring treatment and making a specific diagnosis.