Recent epidemiologic studies quote a prevalence of 5,2% to 63% for dry eye depending on definition. Many risk factors have been identified, among other things the female gender. Dry eye interferes significantly with quality of live. Measurement of the change in temperature and humidity during blinking turned out to be a reliable diagnostic tool. Videokeratoscopy explains well-known visual impairments related to dry eye and, along with lipid film interferometry, provides insight into tear film dynamics. The importance of tear film proteins is underestimated. Among therapeutics for symptomatic relief hyaluronic acid proved to be particularly useful but also the sequence of lid hygiene, warm compresses and lid massage is fundamentally important. The effectiveness of punctum plugs is ascribed considerably to a more efficient impact of essential tear film components. Topical cyclosporine A, INS365, 15(S)-HETE as well as topical androgens represent a whole new class of drugs for causal therapy of dry eye.