In fact, arid eyeballs have become so prevalent, experts say it's the No. 1 reason people go to see an eye doctor.
That's not too surprising, considering an estimated 20 million to 30 million Americans suffer from mild dry eyes and 9 million to 12 million have a moderate to severe case. Among those over age 50, dry eyes afflict more than 5 million, including up to 25 percent of those over 65.
"In patients over 50, dry eye is the most prevalent — and under-recognized and undertreated — condition out there," says Alan Carlson, M.D., professor of ophthalmology at Duke University School of Medicine. "Virtually everyone over 55 has some degree of dryness."
While artificial tears can provide some relief — one of the reasons sales of the over-the-counter eye drops are a whopping $3.8 billion annually — it's important to address the underlying causes. Left untreated, dry eye, according to Carlson, can lead to permanent changes to the structure and function of the eye.
Not sure what's causing dry eye? Here are five surprising culprits.
Mites. Microscopic bugs clinging to your eyelashes might sound like something out of a horror movie, but the critters are real — and a real cause of dry eye.
Demodex mites are commonly found on the face and eyelids, and their numbers increase as we age. They burrow into the meibomian glands in the eyelids to feed on sebum, the oily secretion that lubricates the eyes. Robbing the eyes of sebum can lead to dry eye. In one study, 84 percent of those over age 60 and 100 percent of those over 70 had demodex mites.
Those with the skin disorder rosacea also tend to have 15 to 18 times more mites than healthier patients.
Still, the mites are controversial: Carlson believes their prevalence has been "overstated," and notes that cases in his practice are rare.
What to do: If you get a diagnosis of demodex mites, using a combination of tea tree oil, warm compresses and eyelid massage can help get rid of the mites and reduce inflammation that causes dry eye.
C. Stephen Foster, M.D., professor of ophthalmology at Harvard Medical School and founder of the Massachusetts Eye Research and Surgery Institution, suggests applying a warm washcloth over the eyes and using vertical strokes to massage the upper and lower eyelids.
Medications. Both prescription and over-the-counter drugs ranging from antidepressants to antihistamines to blood pressure medications can cause a reduction in tear production, leaving your eyes dry, red and irritated, according to Christopher Starr, M.D., associate professor of ophthalmology at Weill Cornell Medicine in New York.
"You treat one [medical condition] but exacerbate another one," he explains. "When you prescribe medications that have dry eyes as a side effect, you have to also prescribe treatment for dry eyes."
What to do: To increase tear production, Starr often prescribes Restasis, which reduces inflammation. Over-the-counter drops can also bring temporary relief, but if you're using artificial tears more than four times a day, look for preservative-free brands (check the labels). "In higher doses the preservatives commonly found in drops, benzalkonium chloride in particular, can be a bit toxic to the ocular surface," Starr says. "If you're only using lubricants a few times a day, then a preserved drop is usually OK."
Screen time. Whether it's constantly binge-watching television or spending hours in front of your computer, all that nonstop screen time is making your eyes burn.
"When you spend too much time staring at screens, you blink less and your blink quality is reduced," says Carlson.
A normal blink rate is five to eight times a minute; the blink rate drops to twice a minute when you're in front of a smartphone, computer or tablet. When you blink less, the meibomian glands that help keep the eyes lubricated get blocked, tears evaporate and your eyes feel dry.
What to do: To increase blink rate, Carlson suggests doing blinking exercises using the 20/20/20 rule: Every 20 minutes, take a 20-second break from the screen and look at an object 20 feet away. You can even download screensaver apps like Sprint's Evo that will pop up to remind you to take a blink break.
Medical conditions. The likelihood of developing dry eye increases if you have an autoimmune disease such as rheumatoid arthritis, rosacea or lupus. In fact, dry eye is often an early indicator of a chronic inflammatory disease called Sjögren's syndrome. The reason, according to Starr: Autoimmune diseases target the ocular surface, causing inflammation that leads to dry eye.
Diabetics are also at risk for developing dry eye. In a study published in BMC Ophthalmology, more than 70 percent of diabetics with diabetic retinopathy also had dry eye; diabetic women over 50 were especially at risk. Researchers believe reduced sensation in the cornea, poor tear production and evaporation are the likely causes.
What to do: In addition to keeping diabetes well-controlled and treating autoimmune diseases to reduce inflammation, a 2013 study found that omega-3 fatty acids helped relieve eye dryness in 65 percent of patients after three months.
Subjects in the study took a 500-milligram omega-3 capsule twice a day, but Starr suggests that eating foods rich in omega-3 fatty acids, such as fish and flaxseed oil, can be just as effective. "Omega-3s will help build the oily layer of tear film," he says.
He also suggests using a humidifier to keep moisture in the air, and keeping your eyes lubricated with artificial tears.
Age. Your eyes aren't immune to the impact of age-related hormone shifts. As you get older, you produce less androgen, the sex hormone that regulates the lacrimal gland, which controls the secretion of tear film.
"As part of the natural aging process, the liquid-producing cells [in the eyes] die off," says Foster.
Women are especially susceptible because, in addition to declining androgen levels, estrogen — a hormone known to stimulate the eye's oil-producing meibomian glands — is also decreasing. Foster notes that it's common for women to start complaining of dry eye after menopause.
Age-related neurodegenerative diseases such as Parkinson's, which lowers blink rates, are also linked to dry eye.
What to do: Artificial tears or prescription medications such as Restasis can help. In severe cases, Foster notes that a surgical treatment that places tiny plugs, called punctal plugs, made from silicone or acrylic polymer, into the tear duct could alleviate dry eye by slowing the evaporation of tears and keeping the eyes moist. In more than 50 percent of cases, punctal plugs relieved dry eye symptoms, according to a 2015 study.
"Dry eye is common as you age, but it's not something you have to put up with," says Carlson. "There are good treatments available to address the symptoms and improve your quality of life."
Jodi Helmer writes frequently about health topics for AARP.