Teardrops serve an essential function for your eyes — they keep them moist and clean and provide them with essential nutrients. But when your eyes don’t produce enough, you may develop a condition known as dry eye.
By Dennis Thompson Jr.
Medically reviewed by Lindsey Marcellin, MD, MPH
Sine Tears aren’t just for crying. They are a vital part of maintaining healthy eyesight, always acting to moisturize and lubricate your corneas. If something happens to affect the amount or quality of the teardrops you produce, you could wind up with itchy, scratchy, aching eyes — symptoms of a condition known as dry eye syndrome.
The cornea is the dome-shaped invisible surface covering the parts of the eye that take in light and control vision — the iris and the pupil. The cornea protects those crucial eyesight mechanisms from outside contaminants like dust, germs, and debris. Because it covers the light-perceiving portions of the eye, the cornea is made of clear tissue. That means it contains no blood vessels to provide it nourishment or protect it from infection.
Instead, the cornea receives its nutrition from tears. Every time you blink, tears created by the lacrimal gland spread across your eyeballs. These tears act to lubricate the entire outer surface of the eyeball and keep your corneas clean and healthy. Tears also help wash away foreign matter that might damage the cornea, keep the cornea moist, and reduce the risk of eye infections. In emergency situations, like when an eyelash or dust particle lands on your eye, tear production increases,
Dry Eye: When You’re Not Producing Enough Tears
Dry eye syndrome occurs when:
Not enough tears are produced. For various reasons, including inflammation of the lacrimal glands, you don’t produce enough tears to keep your corneas properly fed and protected. Tears of insufficient quality are produced. Your tears contain a combination of oil, water, and mucus. The oil in tears works to “seal” the tears in and help prevent evaporation before the corneas have been fed and lubricated. Mucus works to make sure the tears spread evenly across the eye. If you are not producing enough oil or mucus, your tears may not be able to do their best at protecting the corneas. Symptoms of dry eye include:
A burning or stinging sensation in the eye A gritty feeling, as though something is in your eye Pain and irritation in your eye Blurred vision Eye fatigue, including the inability to read or work on a computer for extended periods What Causes Dry Eye?
Age is the most common risk factor for dry eyes. In fact, dry eye is considered a normal part of aging. Nearly 5 million Americans 50 or older have dry eye, including more than 3 million women and more than 1.5 million men. Dry eye tends to become more common in women following menopause, and women who go through premature menopause are more likely to have eye damage from dry eye.
Other causes of dry eye include:
Medications. Certain types of drugs can cause dry eye. These include antihistamines, decongestants, antidepressants, and blood pressure medications. Medical conditions. Eye or eyelid infections and diseases that cause inflammation can contribute to dry eye by affecting tear production, as can allergies. People with diabetes, rheumatoid arthritis, and thyroid problems are also at increased risk for dry eye. In addition, vitamin overuse or deficiency can be a contributing factor. Environmental conditions. Tears may evaporate more quickly when eyes are exposed to smoke, dry air, or wind — likely resulting in dry eye. Staring at a computer screen or television also can cause dry eye if you unconsciously start blinking less frequently. Eyesight correction. Long-term contact lens use can cause dry eye. People who have undergone laser vision correction also could experience dry eye because of a change in the shape of the cornea, which may have an effect on the spread of tears across the cornea. Dry eye can and should be treated for the health and comfort of your eyes.