When the human eye is not sufficiently moistened due to a reduced tear volume or a changed composition of the tear fluid, it leads to a condition commonly referred to as "dry eye" and medically known as the Sicca syndrome. Dry eye has become one of the most common eye diseases, affecting over 11 million Central Europeans. Numerous factors contribute to the symptoms experienced by patients who visit an ophthalmologist today, including burning, itching, a foreign body sensation in the eye, or red eyes. This book provides an overview of the current state of research on dry eye as well as the treatment options currently available.