Dry eye is one of the most common eye conditions and is one of the most frequent reasons for seeing an eye doctor. Dry eye develops when the eyes are not sufficiently and properly lubricated. Having a healthy and adequate layer of tears on the eye is essential to keeping the eyes healthy, seeing well, and keeping them comfortable. The tear film has three layers 1) the lipid (oily) component, 2) the aqueous (watery) component, and 3) the mucin (mucous) component. Each component of the tear film serves an essential function. If any of these parts is deficient or unhealthy, the tear film will become unstable and inadequate and dry eye symptoms will develop. The consequences of dry eye can vary from subtle and constant eye irritation, to significant ocular inflammation, and rarely to scaring on the surface of the eye. Dry eyes cannot always be eliminated, but it can usually be well controlled.