They say oil and water don’t mix, but tell that to your eyes. The tears produced by healthy orbs have a lubricating layer of watery tear and oil, and without this combo, your eyes can be in serious trouble.
That's where dry eye syndrome comes in. Different from just a one-time episode of dry-feeling eyes, this is an umbrella term for a variety of problems in which tear production is faulty. Ophthalmologists tend to lump dry-eye sufferers into two camps: Those whose tears are in short supply and others whose tears are lacking in oil, causing moisture to evaporate too quickly from the eye’s surface. Some people experience a combination of the two.
Dry-eye sufferer Natalia Warren is chair and co-founder of a nonprofit Not A Dry Eye Foundation, created by a group of patients who “suffered untold agonies” before getting proper diagnosis and treatment. “My symptoms were so severe that I felt like I had tissues stuffed under my eyelid,” she said.
Here are some common and troubling dry eye symptoms:
Swollen blood vessels on the white, outer layer of the eyeball can give eyes a crimson hue or make them look completely bloodshot. If you don't have an eye infection or allergies, it’s a good bet they’re red because your eyes are super dry.
“If you have lack of tears, then the cells on the surface of the eye cry out in pain because they’re not being protected,” said Steven Maskin, M.D., medical director of the Dry Eye and Cornea Treatment Center in Tampa, Fla. “Chemicals are released that cause inflammation,” and redness is a byproduct, he explained.
Redness and inflammation may be due to meibomian gland dysfunction, meaning the tiny oil glands lining the eyelids aren’t producing or releasing sufficient lubrication.
Dry eyes often feel gritty, sandy, or gravelly, like the desert.
Some people describe a foreign body sensation, as if something’s painfully lodged in one or both eyes. (Dirt or makeup can get stuck in the eye, so it’s important to have it checked out.)
At the doctor's office, the symptoms many people describe may be shown to be due to dry patches on the cornea, the transparent front layer of the eye.
“The surface of your eye just literally dries out, the cells dry out and cause these micro-abrasions,” explained Amy Lin, M.D., associate professor of ophthalmology and visual sciences at the University of Utah Moran Eye Center in Salt Lake City. Fortunately, it doesn’t necessarily cause permanent damage. “Those dry spots heal when the eyes are more moisturized,” she added.
People with insufficient watery tears may experience photophobia, or extreme sensitivity to light. As Not A Dry Eye Foundation explains, it can be temporary or constant and occur in all types of light.
People with photophobia may squint or shut their eyes when exposed to light. The amount of discomfort may vary, too. Some people may experience extreme pain when nerve endings in the eye come in contact with light. Others may complain of light being too bright.
Light-sensitive cells in the retina, the layer of tissue lining the back of the eye, may be responsible for the discomfort, according to the North American Neuro-Ophthalmology Society. It’s thought that these cells may have connections with the nerve that is responsible for relaying sensory information to the head and face.
The eyes endure a litany of insults: wind, smoke, dry air, cleaning product fumes, you name it. An inadequate tear film on the eye exposes nerve endings to whatever wafts in their path.
Not A Dry Eye Foundation’s Ms. Warren says the cornea, or window of the eye, has 300 to 600 times more nerve endings than any other part of the body. “So imagine a pin prick in your finger, but the pin is 600 times wider.”
Any enclosed space with forced vented air, like air conditioning in a home, office, or car, or even an indoor fan, can make dry eyes worse, Dr. Lin said.
There can also be eye sensitivity to fumes (even from foods while cooking) and perfumes, the foundation says.
Eyes need adequate lubrication to feel comfortable, and blinking plays a crucial role. That’s how meibum, the oily substance that keeps the eyes lubed up, is released. When people engage in activities requiring intense focus, they may not blink enough. Or they may not sufficiently close their eyes when they blink. That may be one reason dry eye patients experience a burning sensation in the eyes or on the eyelid margins.
“When you have tears that evaporate readily, it leaves the cornea desiccated, and that gives you a sense of burning,” explained Dr. Maskin, author of the book Reversing Dry Eye Syndrome.
We’re talking viscous strings of eye goo, people. It’s more common in individuals with moderate to severe dry eye and may occur in combination with other conditions, like an infection or allergy.
Here’s what happens: People who don’t have a good, watery layer on the eye surface experience friction and strain when they blink. And that causes the tear film to secrete more mucus to make up for the missing layer of moisture.
Esen Akpek, M.D. professor of ophthalmology at the Johns Hopkins University School of Medicine’s Wilmer Eye Institute, says it’s a “compensation mechanism of the eye to overcome the lack of good volume.”
Trouble is when people wipe their eyes to clear the mucus, it can cause further insult to the eye surface and trigger more inflammation, said Dr. Akpek, who also serves as director of the Ocular Surface Disease and Dry Eye Clinic at Johns Hopkins. And so begins a vicious cycle.
It seems counterintuitive: Why would people with dry eyes have watery eyes?
Dry, irritated eyes “turn on the water works” in an attempt to flush out whatever’s bugging them, Dr. Lin explains. But the reason the eyes are irritated in the first place is because they’re dry.
Patients who complain of excessive tearing often have evaporative dry eye syndrome, Dr. Akpek said. When the eye’s oil layer is inadequate, the tear layer quickly evaporates, causing excessive tearing.
Contact lens wearers sometimes feel the need to reduce the amount of time they use contacts or ditch the lenses altogether because their eyes become so uncomfortable. Roughly half of contact lens wearers report dry eye symptoms. Long-term contact use can lead to loss of sensation in the cornea, the eye’s clear surface, Dr. Maskin explains. It’s the same for patients who’ve undergone LASIK eye surgery or other corneal procedures.
“When the sensitivity of the cornea is altered, it can lead to reduction in tear secretion, decreased blink and dry eye,” he says.
Should you switch to wearing glasses? Maybe or maybe not. With proper diagnosis and management, many people can comfortably continue wearing contacts, according to a report in Review of Optometry.
Blurry vision is a common symptom of dry eye, one that typically comes and goes. Vision may clear in the morning, after a night of shuteye. But when dryness sets in during the day, so does foggy vision.
“When the tear film is robust and smooth, then you can see very well through it,” Dr. Lin explains. “But if the tear film is kind of ratty and it’s not covering the eye very well, then it’s like ripples on the surface of a pond or a lake.”
Dr. Maskin has seen patients whose doctors referred them for magnetic resonance imaging for blurred vision when what they had was dry eye. He offers two simple tests: First, try blinking and if your vision improves, you probably have dry eye. And second, add a drop of artificial tears to each eye (which are available over-the-counter). If it’s dry eye, the blur should disappear.
If you’re feeling emotional, but the tears won’t come, it could be a dry eye symptom. Keep in mind that reduced tear production may also result from any number of factors, from hormonal changes to medication side effects.
It’s also one of the hallmarks of Sjogren’s syndrome, an autoimmune disorder that causes dry eye, mouth and vagina.
Eyes or eyelids that feel heavy are a possible indicator of dry eye.
Insufficient tear film can leave your eyes fatigued, “and your eyelids try to droop a little bit in order to protect the eye surface,” Dr. Akpek explains.
The heaviness may also be related to meibomian gland dysfunction. This occurs when oil-secreting glands in the lids fail to produce enough oil to keep the tear film moist, or the oil, called meibum, becomes too thick to do any good. The glands themselves can become clogged and crusted.
Staring at phones, computer screens or other electronic devices for extended periods of time is not very conducive to maintaining moist eyes. Neither is reading a book. When people are engaged in these activities, they tend blink at one-third of the normal rate, says Dr. Lin. Is it any wonder that their eyes begin to dry out?
Even kids are showing up with dry eye, she said.
To stave off dryness, follow this rule of thumb: Take a break every 20 minutes by looking 20 feet away for 20 seconds.
Having night vision problems behind the wheel? It could be a sign of dry eye.
Any activity that requires intense focus, say, maneuvering a vehicle from point A to point B, tends to cause people not to blink as much as they normally would. Blinking, of course, is a crucial function for keeping the eyes lubricated.
Headlight and street light glare may also be bothersome to people with dry eye.
What’s more, nighttime driving may be more difficult simply because the eyes are typically at their driest at the end of the day.
Although that may seem extreme, when dry eye symptoms become severe, they can completely overwhelm people and contribute to depression.
“Suicidal thoughts among dry eye sufferers are more common and more alarming than anyone knows,” says Ms. Warren, of Not A Dry Eye Foundation. Most of the organization’s founding board members had suicidal thoughts at some point, she says. “I was one of them.”
Dr. Maskin agrees, and has seen about two dozen patients who planned or tried suicide in his 25 years of practice. He urges people to be their own advocates for symptom relief.
“All bad dry eye starts out as annoying nuisance, or just minimal dry eye,” he says. “If you let it build up over time, you become a significant risk factor for more significant dry eye.”