This is a tear and ocular surface disease that results in symptoms of discomfort, blurred vision and tear deficiency or imbalance. The tear film layer is of vital importance in supplying and moisturizing the ocular surface and maintaining a clear corneal tissue.  Being most common in autoimmune diseases such as Sjögren's syndrome, dry eye develops as a result of tear deficiency or excessive evaporation of tears in cases of absence of the lacrimal glands, occluded ducts of the glands, inflammation of the eyelids, contact lens use and vitamin A deficiency.  Many oral drugs, computer use, ambient humidity, habits such as smoking and other external factors are also influential in the development of dry eye. Appropriate treatment for dry eye is given after a detailed eye examination and tests evaluating the quality and amount of tears.