What is Dry Eye?Many times in our lifetime, we will experience a "foreign body sensation" in our eye. That usually happens if the wind blows dust, an allergen or a foreign body into our eye or under an eyelid. This should not be dismissed as just an uncomfortable feeling. It needs to be remedied. It cannot be allowed to linger or fester. For many, the feeling of grittiness, dryness, burning or stinging or even excessive tearing cannot be relieved simply, or with over the counter methods. It may be the sign of a chronic condition known as dry eye syndrome. Yes, even tearing eyes are a sign of dry eye. The tears your eyes produce are necessary for overall eye health and clear vision. Dry eye means that your eyes do not produce enough tears or that you produce tears that do not have the proper chemical composition. Dry eye is more common as we age. It can also be caused by blinking or eyelid problems, medications like antihistamines, oral contraceptives, and antidepressants, a dry climate, wind and dust, general health problems like arthritis or Sjogren's syndrome and chemical or thermal burns to your eyes. If you have dry eye, your symptoms may include irritated, scratchy, dry, uncomfortable or red eyes, a burning sensation, excessive tearing, blurred vision, or a feeling of something foreign in your eyes. Excessive dry eyes may damage eye tissue, scar your cornea (the front covering of your eyes) and impair vision and make contact lens wear difficult. Any condition that reduces the production, alters the composition or impedes the distribution of the preocular tear film (POTF) may cause a noticeable irritation to the structures of the front surface of the eye and a degradation of vision. These conditions are often related to problems with the structure or function of the eyelids, cornea, or conjunctiva. Depending upon the severity of symptoms, individuals may be limited in their ability to see clearly and comfortably and may be at increased risk of developing secondary infection or chronic inflammation that may not respond to treatment.
The two most commonly encountered ocular surface disorders are tear film disorders and blepharitis. Additional subclassifications include those dry-eye states associated with systemic connective tissue disorders, specifically Sjogren syndrome (SS). With regard to lipid deficient tear-film disorders, the involvement of meibomian gland dysfunction (MGD) has been proposed.