Tear substitutes form the mainstay of treatment. They are aqueous solutions containing polymers that determine their viscosity, retention time and adhesion to ocular surface. They are cellulose derivatives like HPMC-hydroxypropyl methylcellulose and CMC-carboxymethycellulose, polyvinyl derivatives like polyvinyl alcohol, chondroitin sulfate and sodium hyluronate. Artificial tears provide improvement in symptoms of eye irritation, blurred vision and visual contrast sensitivity. However…