Many people are complaining that they often have discomfort feelings in their eyes. It feels like the presence of a foreign body in the eye though when they examine it there is no any. This feeling is caused by the dryness of their eyes or, to be more exact, the dryness of the corneal surface. The membrane of tears produced by lacrimal gland protects our eye and provides the proper sharpness of the vision. It is a complicated system whose functionality depends on many factors.