The eye has a tear film which coats the outer layer of the eye. This tear film is very important for the lubrication and comfort of the eye as well as for the clarity of vision. As we age, this protective tear film diminishes, and leaves the eye more exposed to the drying effects of the air, wind and dust. In many people the dryness is worse in the afternoon and evening.
Dry eye is not caused by a lack of tear production. In fact, during dry eye, the eye can still make so many tears that many patients complain of wet eyes and tearing with this malady. That's because the dryness causes the eye to produce more tears in an effort to replace the tear film. Dry eye is probably the most common problem seen in the eye doctor's office.
Dry eye symptoms include burning, stinging or a gritty sensation which may come and go depending on many factors. Itching, tearing and light sensitivity may also occur. Occasionally long strings of mucus can be stretched from a dry eye.
Blinking is very important for the maintenance of the tear film. When performing such activities as reading or working on a computer, we blink less frequently. This aggravates the symptoms of dry eyes. Sometimes environmental factors can also aggravate dry eye symptoms. Dry weather, either in hot or cold temperatures, robs the eye of needed lubricants. Cigarette smoke, fumes, dust and airborne particles are common irritants. In most patients, this condition is not associated with systemic disease.
Treatment helps in most patients. We cannot cure this condition, so treatment is an ongoing project. Usually artificial tears, available over-the-counter, soothe the eyes and give temporary relief. These artificial tears work for only an hour or two, at best, and must be repeated at frequent intervals. Ointments last longer, but they blur vision and are most effective at night.
Newer techniques to treat dry eye include plugs which block the tear duct. These plugs can be placed in the two tear ducts, top and bottom, in both eyes or in only the lower ducts. Some test plugs are also available which dissolve a few days after insertion. If the dry eye symptoms disappear when the temporary plugs are inserted, then permanent plugs should be considered as a treatment option.