Tear Ducts

When you stop to think about it, crying is really a mixed signal. You win the lottery and cry tears of joy. You lose the whole pot playing the slot machines in Vegas, and you shed tears again--this time, tears of regret. As you hitchhike across the Nevada desert toward home, you get sand in your eye--fueling yet more tears.

Tears are salty, watery secretions that keep two parts of the eye constantly moist. They flow over the cornea--the transparent coating of the eye--and they lubricate the conjunctiva--the membrane covering the white of the eye and lining the inside of the eyelids. Doing their job on the cleanup crew, tears also wash away stray bits of dust and grit and help keep your eyes infection-free with a natural antiseptic called lysozyme.

Even though one tear is as good as another, they come from different sources. The tears that constantly keep your eyes moist, called the basic tear secretions, are produced on the conjunctiva and also in the eyelids. The tears that you cry over spilled milk, lost loves and squandered savings are reflex tears, generated from what''''s called a lacrimal gland in the upper, outer corner of your upper eyelid. These tears spring into action when you get something in your eyes as well.

Some of this overflow ends up in your tear ducts, the pinpoint-size holes located in the inside corners of your lower and upper eyelids. Rather than produce tears, tear ducts act as the drainage ducts through which the tears get washed into your nasal passages. That''''s right--when you blow your nose after a good cry, you''''re actually sending a spray of tears into your tissue.

Dry Times

You''''re not likely to pay much attention to everyday tear activity until the wells go dry. When your eyes are dry, however, they feel scratchy or irritated, or they burn. About 90 percent of dry eye cases are caused by a condition called keratoconjunctivitis sicca (KCS), which is just an elaborate name for what happens when you have a deficiency in tear production.

Although researchers don''''t know why, the change in the balance of hormones during pregnancy or menstruation can change women''''s tears. Menopausal or postmenopausal women are most often affected by KCS. "The tear film may be related to hormonal status," says Mary Gilbert Lawrence, M.D., ophthalmologist at Yale University School of Medicine and instructor of ophthalmology at the Manhattan Eye, Ear and Throat Hospital. "Many of my women patients find that during pregnancy they can''''t wear their contact lenses or that they need to use more lubricating drops in order to be more comfortable. In fact, many women say that their eyes feel dry at certain times of the month."

If you have dry eyes, and hormonal changes aren''''t the culprit, maybe you can blame medications. A few of the drugs that have this effect are the antihistamines, tricyclic antidepressants and other medications as well, so check with your doctor or pharmacist.

What, if anything, can you do about dry eyes? Here are some tear tips.

Steam up the air. Using a humidifier set at about 80 percent humidity helps moisturize the air, says Thomas Gossel, R.Ph., Ph.D., professor of pharmacology and toxicology and dean of the College of Pharmacy at Ohio Northern University in Ada. If your humidifier does not mark off percentages, set it at the maximum steaming level. Since the cornea is always exposed to the air, you''''re putting moisture on the cornea when you add moisture to the air, he notes.

Drop in. Over-the-counter artificial tears are the best remedy for dry eyes, says W. Steven Pray, R.Ph., Ph.D., professor of nonprescription drug products at Southwestern Oklahoma State University College of Pharmacy in Weatherford. Follow the manufacturer''''s directions when you''''re using the drops. Usually, that means two or three drops in each eye. It''''s not harmful to use more, but not helpful either, he notes. The excess will just run out of the eye.

Keep some drops out. Avoid any eye care products that constrict the eye''''s blood vessels, advises Dr. Pray. These drops only aggravate dry eyes.

Drip the drops correctly. The best way to apply eyedrops is to pull your lower eyelid down, says Dr. Pray. Then tilt back your head until you''''re looking up at the ceiling and drop in the artificial tears without touching your eye or eyelid with the applicator.

When you flood your eye with drops, the drops will run down your tear ducts and go down into your nose, so you end up swallowing them. To avoid that, after you put in the drops, place your thumb and forefinger in the corners of your eyes, tilt back your head and squeeze gently for about five minutes. Try to hold this position for the full five minutes, adds Dr. Pray. The drops will be less effective if you give them less time.

See also Eyes