The following classification has been established: First, a classification of the etio-pathogenesis, distributed in ten groups: age-related, hormonal, pharmacologic, immunopathic, hyponutritional, dysgenic, infectious/inflammatory, traumatic, neurologic and tantalic. Second, a classification of the affected glands and tissues, which under the acronym of ALMEN includes the Aqueo-serousdeficient, Lipodeficient, Mucindeficient and Epitheliopatic dry eyes, and the Non dacryological affected exocrine glands (saliva, nasal secretion, tracheo-pharyngeal secretion, etc). And thirdly, a classification of severity, in three grades: Grade 1 or mild (symptoms without slitlamp signs), grade 2 or moderate (symptoms with reversible signs), and grade 3 or severe (symptoms with permanent signs).