Dry eye is a fairly common condition in which there are insufficient tears to lubricate and nourish the eye or the quality of the tears is somehow diminished. Tears are necessary for maintaining the health of the front surface of the eye and for providing clear vision. People with dry eyes either do not produce enough tears or have a poor quality of tears. Dry eye is a common and often chronic problem, particularly in older adults. When dry eyes become chronically inflamed and irritated, it is common to be diagnosed with dry eye syndrome. Approximately 33% of the world suffers from dry eye.

With each blink of the eyelids, tears are spread across the front surface of the eye, known as the cornea. Tears provide lubrication, reduce the risk of eye infection, wash away foreign matter in the eye, and keep the surface of the eyes smooth and clear. Excess tears in the eyes flow into small drainage ducts, in the inner corners of the eyelids, which drain in the back of the nose. Dry eyes can result from an improper balance of tear production and drainage.

Why Causes Dry Eye Syndrome?

Tears are made up of more than just water. They're a complex mixture of water, fatty oils, proteins, electrolytes, bacteria-fighting substances and growth factors that regulate various cell processes. This mixture helps make the surface of your eyes smooth and clear. Without tears, good vision is impossible.

For some people, the cause of dry eyes is an imbalance in the composition of their tears. Other people don't produce enough tears to keep their eyes comfortably lubricated. Eyelid problems, medications and other causes, such as environmental factors, also can lead to dry eyes.

Inadequate amount of tears or decreased tear production – Tears are produced by several glands in and around the eyelids. Tear production tends to diminish with age, with various medical conditions, or as a side effect of certain medicines. Environmental conditions such as wind and dry climates can also affect tear volume by increasing tear evaporation. When the normal amount of tear production decreases or tears evaporate too quickly from the eyes, symptoms of dry eye can develop. The most common form of dry eyes is due to an inadequate amount of the water layer of tears. This condition, called keratoconjunctivitis sicca or keratitis sicca (depending on which areas of the eye are affected), is also referred to as dry eye syndrome.

Poor quality of tears – Tears are made up of three layers: oil, water, and mucus. Each component serves a function in protecting and nourishing the front surface of the eye. A smooth oil layer helps to prevent evaporation of the water layer, while the mucin layer functions in spreading the tears evenly over the surface of the eye. If the tears evaporate too quickly or do not spread evenly over the cornea due to deficiencies with any of the three tear layers, dry eye symptoms can develop.

Gender or hormonal changes - Although dry eyes can affect both men and women at any age, the condition is more common among women, especially after menopause. This may be due in part to hormonal changes. Damage to the tear glands from inflammation or radiation can hamper tear production. Dry eyes are also associated with some medical conditions such as diabetes, rheumatoid arthritis, lupus, scleroderma, Sjogren's syndrome and vitamin A deficiency.

Contact lenses - Many individuals with contact lenses complain of dry eye. That's because soft contact lenses, which float on the tear film that covers the cornea, absorb the tears in the eyes. There are some options for those who wear contact lenses and find themselves with dry eyes. Visit our Contact Lenses and Dry Eyes area for more information.

Laser Vision Correction - Refractive eye surgeries such as laser-assisted in-situ keratomileusis (LASIK) also may cause decreased tear production and dry eyes. Symptoms of dry eyes related to these procedures are usually temporary.

Poor eyelid function - Through blinking - normally at a rate of about once every 12 seconds - your eyelids spread a continuous thin film of tears across the surface of your eyes. Problems with your eyelids can impair the complex blinking motion required to spread these tears, resulting in dry eyes. Eyelid problems that may develop as you age include an out-turning of the lids (ectropion) or an in-turning of the lids (entropion).

Other eye conditions or diseases - Blepharitis, an inflammation along the edge of the eyelids, also may cause your eyes to feel dry and scratchy.

Medications - The types of common medications, both prescription and over-the-counter (OTC), that can be the causes of dry eyes include:

• Diuretics, drugs commonly used to treat high blood pressure
• Angiotensin-converting enzyme (ACE) inhibitors used to treat high blood pressure
• Antihistamines and decongestants
• Sleeping pills
• Birth control pills
• Certain antidepressants
• Isotretinoin-type drugs for treatment of acne
• Opiate-based pain relievers, such as morphine
• Other causes of dry eyes

Environmental Causes - Dry eyes can be worsened by exposure to many environmental conditions that have a drying effect, such as sun, wind, high altitude, a dry climate, hot blowing air and the dry air that commonly occurs in the cabins of commercial airplanes. In addition, tasks that require intense visual concentration — such as working at a computer, driving or reading — tend to decrease your blink rate, thereby increasing tear evaporation.

What can I do if I think I may have Dry Eye Syndrome?

Request an appointment at the Dry Eye Clinic in Charlottesville, VA for a evaluation of your dry eye and a treatment plan consisting of prescription and over the counter medicines and lifestyle changes that will help control your dry eye symptoms.