Dry eye, or keratoconjunctivitis sicca, is a chronic inflammatory condition of the ocular surface that may cause severe symptoms an 2007 international dry eye workshop (DEWS) defined the disease as follows: "Dry eye is a multifactorial disease of the tears and oc symptoms of discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface. It is accompanied the tear film and inflammation of the ocular surface".