The eye depends on the flow of tears to provide constant moisture and lubrication to maintain vision and comfort. Tears are a combination of water, for moisture; oils, for lubrication; mucus, for even spreading; and antibodies and special proteins, for resistance to infection. These components are secreted by special glands located around the eye. When there is an imbalance in this tear system, a person may experience dry eyes.
When tears do not adequately lubricate the eye, a person may experience:
- Light sensitivity
- A gritty sensation
- A feeling of a foreign body or sand in the eye
- Blurring of vision
Sometimes, a person with a dry eye will have excess tears running down the cheeks, which may seem confusing. This happens when the eye isn't getting enough lubrication. The eye sends a distress signal through the nervous system for more lubrication. In response, the eye is flooded with tears to try to compensate for the underlying dryness. However, these tears are mostly water and do not have the lubricating qualities or the rich composition of normal tears. They will wash debris away, but they will not coat the eye surface properly. In addition, because these emergency tears tend to arrive too late, the eye needs to regenerate and treatment is necessary.
What Causes Dry Eyes?
In addition to an imbalance in the tear-flow system of the eye, dry eye can be caused by the drying out of the tear film. This can be due to dry air created by air conditioning, heat, or other environmental conditions. Other conditions that may cause dry eyes are:
- The natural aging process, especially during menopause
- Side effects of using certain medications such as antihistamines and birth control pills
- Diseases that affect the ability to make tears, such as Sjogren's syndrome, rheumatoid arthritis and collagen vascular diseases.
- Structural problems with the eyes that don't allow them to close properly or a problem with the tear ducts
How Are Dry Eyes Treated?
Though dry eyes cannot be cured, there are a number of steps that can be taken to treat them. You should discuss treatment options with an ophthalmologist.
- Artificial tear drops and ointments. The use of artificial teardrops is the primary treatment for dry eye. Artificial teardrops are available over the counter. No one drop works for everyone, so you might have to experiment to find the drop that works for you. If you have chronic dry eye, it is important to use the drops even when your eyes feel fine, to keep them lubricated. If your eyes dry out while you sleep, you can use a thicker lubricant, such as an ointment, at night.
- Temporary punctal occlusion. Sometimes it is necessary to close the ducts that drain tears out of the eye. This is done via a painless procedure where a plug that will dissolve quickly is inserted into the tear drain of the lower eyelid. This is a temporary procedure, done to determine whether permanent plugs can provide an adequate supply of tears.
- Permanent punctal occlusion. If temporary plugging of the tear drains works well, then silicone plugs (punctal occlusion) may be used. The plugs will hold tears around the eyes as long as they are in place. They can be removed. Rarely, the plugs may come out spontaneously or migrate down the tear drain. Many patients find that the plugs improve comfort and reduce the need for artificial tears.
- Restasis. In 2002, the FDA approved the prescription eye drop Restasis for the treatment of chronic dry eye. It is currently the only prescription eye drop that helps your eyes increase their own tear production with continued use.
- Other medications. Other medications, including topical steroids, may also be beneficial in some cases.
- Surgery. If needed, the ducts that drain tears into the nose can be permanently closed to allow more tears to remain around the eye. This is done with local anesthetic on an outpatient basis. There are no limitations in activity after having this surgery.
For more information on Dry Eye, click here.