This document describes techniques for evaluating the tear film, including vital staining, tear break-up time testing, and the Schirmer test. Vital staining with fluorescein or rose bengal/lissamine green identifies disruptions or deficiencies in the tear film and ocular surface epithelium. Tear break-up time evaluates the stability of the tear film and should be over 10 seconds for a normal result. The Schirmer test measures tear production, with values over 10mm with anesthesia and over 15mm without anesthesia considered normal. Interpretation of results from these tests can provide information about conditions like dry eye syndrome or keratoconjunctivitis sicca.