Dry eye syndrome is caused by a chronic lack of sufficient lubrication and moisture on the surface of the eye.
Its consequences range from subtle but constant irritation to inflammation of the anterior (front) tissues of the eye.
Dry eyes also are described by the medical term, keratitis sicca, which generally means decreased quality or quantity of tears. Keratoconjunctivitis sicca refers to eye dryness affecting both the cornea and the conjunctiva.
Dry Eye Symptoms
Persistent dryness, scratchiness, red eyes and a burning sensation are common symptoms of dry eyes. These symptoms alone may prompt your eye doctor to diagnose dry eye syndrome.
Dry eyes can become red and irritated, causing a feeling of scratchiness.
But sometimes your eye doctor may want to measure the amount of tears in your eyes. A thin strip of filter paper placed under the lower eyelid, called a Schirmer test, is one way to measure tear production.
Another symptom of dry eyes is a “foreign body sensation,” which is a feeling that something is in your eye.
And it may seem odd, but dry eye syndrome also can cause watery eyes. This is because dryness on the eye’s surface sometimes will overstimulate production of the watery component of your tears as a protective mechanism.
What Causes Dry Eyes?
Tears bathe the eye, washing out dust and debris and keeping the eye moist. They also contain enzymes that neutralize microorganisms that colonize the eye. Tears are essential for good eye health.
Tears are complex, containing many different essential elements, including oils produced by special glands in the eyelids called meibomian glands. These oils prevent evaporation of the tears.
Smartphone Use Linked to Dry Eye in Schoolchildren
April 2014 - There might be another cost associated with children using smartphones besides a large monthly bill from the phone company: It could be causing kids to develop dry eye disease at an early age. That’s the finding of a new study published in this month’s issue of Journal of Pediatric Ophthalmology and Strabismus.
Researchers in Korea evaluated risk factors for dry eye disease among schoolchildren who used a variety of video devices, including smartphones. They examined 288 children and classified them as either having dry eyes or having a normal, moist eye surface (control group). Each child completed a questionnaire concerning the types of video devices they commonly used (computer, smartphone and television) and the amount of time they spent using each device.
Among the participants, 28 children (9.7 percent) were diagnosed as having dry eyes, and 260 children (90.3 percent) comprised the control group. Smartphone use was more common in the dry eyes group than the control group (71 percent vs. 50 percent), and increased daily duration of smartphone use was associated with increased risk of dry eye disease, as was the total hours per day spent using all video devices combined.
One interesting finding is that increased duration of computer use and television viewing measured separately did not increase the risk of dry eye disease.
The study authors concluded that smartphone use is an important dry eye disease risk factor in children, and that parents should monitor the amount of time their children spend using video displays, especially smartphones, on a daily basis. - G.H.