This document discusses tear film dysfunction and dry eye. It begins with an introduction to the tear film, its components and functions. Various tests to evaluate tear film such as tear film breakup time, Schirmer's test, Rose Bengal staining, and Phenol Red thread test are described. Causes of tear film instability and diseases related to tear film dysfunction including evaporative dry eye and obstructive epiphoria are explained. Early signs of tear dysfunction and methods to check the tear outflow mechanism like Jones tests are also summarized.