Your eye may be red as a sign of irritation. The normal tear film has three layers and several key functions. This helps tears from evaporating and is made by meibomian glands. The tear film is critical as it is the first surface that light hits as it enters your eye. It provides the cornea with nutrients, oxygen and protection from infection.
Many different things can cause dry eye syndrome.
The normal aging of tear glands, as well as specific diseases and disorders, may cause changes in the amount and condition of tears produced. Excessive evaporation of tears can also cause dry eye syndrome. Patients with thyroid disease may also experience dry eye syndrome caused by excessive evaporation. Sj gren's syndrome is an immune system disorder which is characterized by inflammation and dryness of the mouth, eyes, and other mucous membranes. Tear production may be limitied as the the lacrimal gland is affected.