Dry eye syndrome, tear film, pharmacology of eye drops, and toxicity.

Over the past years, the main parameters used for the diagnosis of dry eye have been outlined: there is now substantial effort to bring them into correlation with each other, resulting in easier diagnosis of the diseases that appear to cause dry eye. Although increasing awareness of the plethora of dry eye diseases makes the differential diagnosis and the treatment difficult, the increased availability of optimized artificial tears and tear substitutes, especially viscoelastics, does allow easier relief of the most serious symptoms of dry eye disease. Improved topical treatment, in turn, allows various treatments, such as excimer laser treatment, to be performed, even in dry eyes. This, together with the identification of tear substitutes as a major research target and a better understanding for the psychological tasks of chronic dry eye diseases, offers a good basis toward further improvements.