What is Dry Eye Syndrome?
Dry Eye Syndrome is a condition affecting the tear system. While the term dry eyes may sound simple, the causes of the problem are actually quite complex. Dry eyes (keratoconjunctivitis sicca) are due to a problem with the quantity or quality of the tears in the eye, or sometimes a combination of both.
Symptoms, causes, and treatment options vary widely. It’s estimated that one in every eight adults, or 33 million Americans, have some form of dry eye syndrome. People of all ages can suffer from dry eyes. The condition can be mild or severe, with mild cases being more of a nuisance that’s fixed with a drop of artificial tears, and severe cases causing poor vision that may need surgery.
Causes of Dry Eyes
Let’s take an in-depth look at the various medical conditions and medications that can cause dry eyes. As noted above, dry eyes happen from one of two factors. Either your tear system is not producing enough tears or the produced tears are not keeping your eyes moisturized.
The tear system is complex: Tears carry nutrients to the cells on the surface of the cornea (the front surface of the eyeball) and remove dead or damaged corneal cells. Tears also keep debris away from the cornea, allowing light to enter the eye unimpeded—a necessity for clear vision.
To function normally, the cornea must be covered at all times by a coating of tears called the tear film. Tears are made up of oil, water, and mucous.
Here is a closer look at each layer of the tear film:
- The oily layer is the outermost layer. It is produced by the meibomian glands, which are found in the eyelids. The oily layer floats on top of the tear and acts to slow the evaporation of tears from the surface of the eye.
- The watery layer, or the middle layer, is a major part of the tear film. It is produced by the lacrimal glands, which are located in the upper outside portion of each eyeball socket. Tears originate from the outer part of the eye (toward the ear) and are wiped across toward the inner part (closer to the nose).
- The mucous layer, also known as the mucin, is the innermost layer, which is produced by cells in the conjunctiva and cornea. It is the layer that touches the eye and acts as a detergent that allows the tears to spread smoothly and evenly over the cornea.
Here’s a closer look at the types of tears:
Tears are mostly made of water, and are produced primarily by the lacrimal glands. The eyes produce three types of tears: basal tears, reflex tears, and emotional tears, any of which can trigger the lacrimal gland to secrete even more of the watery component. Here is a look at the different types of tears:
- Basal tears provide lubrication between the cornea and eyelid. They protect the eyes from dust, bacteria, viruses, fumes, and other foreign particles. Basal tears are the normal level of wetness that our eyes should have at all times.
- Reflex tears are the eyes’ response to strong fragrances or fumes, wind, or even spicy foods. Reflex tears are sent out like an army of troops, with the goal of washing or flushing away foreign substances.
- Emotional tears are the eyes’ response to strong emotion.
Certain foods can indirectly cause dry eyes. Chocolate, colas, coffee, and tea all contain caffeine, which robs your body of moisture. Try avoiding or limiting these foods and drinks.
This can also be a major problem. This may seem counterintuitive, but dry eyes cause a reactionary increase in tear secretion that causes “watery eyes”—and this increase in tear flow actually can make the dry eye worse! In other words, your eyes are dry and irritated.
This irritation causes the eyes to feel as if there were foreign particles on them. This in turn causes the eyes to water in order to try to wash these foreign particles out.
Other causes of dry eyes include:
Blockage of the tear ducts or medications that inhibit the production of tears. This problem often leads to chronic dry eyes, as the person is not able to manufacture tears and the eyes are not sufficiently lubricated. Tears evaporate rapidly, and the eyes are not cleaned properly.
Environmental factors can also play a role. Dusty air, dry or windy weather, or fumes like cigarette smoke can evaporate tears much speedily or hamper their effectiveness. This is especially a cause for dry eyes in contact lens wearers, as the lenses absorb lubrication. Contact lens wearers usually experience dry eyes because the contacts seem to dry out the eyes faster. Many contact-lens wearers regularly require rewetting drops.
Working or entertainment can also cause dry eyes. People who spend a lot of time watching TV or using a laptop may suffer eyestrain and dry eyes due to infrequent blinking. Dry eyes can also be caused by a vitamin A deficiency, by some medications, or by some diseases.
Medical Conditions That Cause Dry Eyes
There are many medical conditions that can cause your eyes to dry out. Here’s a look at some of them:
- Sjogren’s Syndrome: This is a non-life threatening yet devastating disease that causes excessive dryness throughout your body. Its victims are women, and it’s often misdiagnosed as menopause.
- Rheumatoid Arthritis: This is an autoimmune disease that causes chronic inflammation of the joints. It can also cause inflammation of the tissue around the joints. Inflammation also occurs around the eyes and mouth, which causes both to dry out.
- Collagen Vascular Disease: Collagen is a tough, glue-like protein that and shapes the structure of tendons, bones, and connective tissues. Malfunctioning of the immune system can affect these structures causing excessive dryness of the eyes.
- Dry Tear Film: As noted above, your tear film has three layers: Oil, Water, and Mucus. Problems with any one of these layers can create dry eyes.
- Acne Rosacea, Meibomitis, Blepharitis: The oily part of the tear film can be depleted in all three of these conditions, which overlap one another.
- Foreign bodies in the Eye: Any foreign body falling into the eye is an irritant and can provoke a cycle of inflammation, either causing dry eyes or making them much worse.
- Congenital Eye Problems: Some people are born with structural problems in their eyes, and some people begin experiencing eye problems as they grow older. In some cases, eyelids don’t close properly, which allows for excessive tear evaporation. Other cases involve failure of the tear ducts to produce tears.
- LASIK: Refractive eye surgeries such as laser-assisted in-situ keratomileusis (LASIK) also may cause decreased tear production and dry eyes. Dry eyes caused by to these procedures are usually temporary.
Medications That Cause Dry Eyes
There are numerous different medications that can either increase the dryness of your eyes or cause your eyes to dry out altogether. People respond differently to medications—one person might experience no side effects, and another taking the same medication will have serious complications.
Here is a look at some medications that have been reported to cause dry eyes:
- Antihistamines: Antihistamines and decongestants may help reduce allergies, but studies show that these drugs also contribute to decrease in tear film production.
- Antidepressants: Antidepressants are known to cause drying of the eyes. Celexa, Lexepro, Zoloft, Wellbutrin, and Paxil are all antidepressants that have reportedly made dry-eye conditions worse.
- Sleeping Pills: Side effects of sleeping pills can include dizziness, confusion, next-day drowsiness, dry mouth, and dry eyes. Over-the-counter sleep aids, as well as prescription sleep aids will cause these side effects.
- Birth Control Pills: Many birth-control pills list dry eye as a side effect, mainly because birth control pills alter your hormones. They say stop the pills, and stop the dryness. On the other hand, pregnancy is also known to cause dry eyes.
- Diuretics: These drugs are mostly used to treat high blood pressure.
- ACE Inhibitors: Angiotensin-converting enzyme inhibitors are mostly used to treat high blood pressure.
- Isotretinoin-Type Drugs: These drugs are mostly used to treat acne conditions.
- Opiates: Opiate-based medicines such as morphine help treat extreme pain.
Dry Eye Symptoms
Dry eye symptoms may appear suddenly or gradually, and can last for hours or days. Although there is no cure for dry eye syndrome, there are things you can do to treat or relieve the symptoms. Common dry eye symptoms include:
- Discomfort (gritty or sandy feeling in eyes)
- Eye pain
- Feeling of a foreign object in eye
- Eye fatigue
- Swollen eyes
- Excessive tearing (as a response to the brain sensing a “dry spot”)
- Itchy eyes
- Eyelid twitching
Dry Eyes and Aging
An estimated 5 million Americans over the age of 50 suffer from moderate to severe dry eye. Aging brings on natural changes that can significantly weaken your eyes. Dry eyes are one of the most common problems older men and women face—as we age our eyes produce less moisture. With age, our eyes become more sensitive to things like wind and light because the body’s mucous membranes produce fewer secretions.
Simple changes in our diets, medications, and environments can help soothe the pain and discomfort. If dry eye is left untreated, the cornea can develop ulcers and other severe eye problems.
Causes of Dry Eyes as We Age
As we age, our body produces fewer tears than when we were younger due to the decrease in secretions from by our mucous membranes. Dry eyes are a very common complaint among older people. Here are a few of the things that cause dry eyes, especially as we age.
- Menopause: Hot flashes, insomnia, vaginal dryness, mood swings, fatigue, and headaches are all associated with menopause. More than 60 percent of women who experience these symptoms also experience dry eyes. Women approaching menopause frequently suffer from dry eyes due to the hormonal imbalances they experience. Dry eyes during this stage in life can also sometimes be a signal that something else is wrong, however, as they are a common symptom of an immune disorder known as Sjogren’s syndrome.
- Decreased Tear Production: As we age, our eyes naturally slow down their tear production. Tears are an important defense for the eyes. Tears not only wash dust away from our eyes, but also soothe them, provide oxygen and nutrients to the cornea, and help defend against eye infections by washing away microorganisms that can form communities in our eyes.
- Medications: Dry eyes can be caused by some high blood pressure medications, antidepressants, heart medications, antihistamines, decongestants, muscle relaxants, sleeping pills, and pain relievers. Drugs for Parkinson’s disease and gastric ulcers will also make your dry eye symptoms worse, as will hormone therapy, particularly estrogen therapy.
Diagnosing Dry Eye Syndrome
Testing for dry eyes can be performed in a number of different ways. A complete eye examination should be performed by your eye doctor. During the course of your examination, you will be asked a series of questions about your overall health, the symptoms you are experiencing, your work environment, your home environment, and perhaps your social activities. These are all important elements in analyzing and treating dry eye syndrome.
It is important to remember that many of the symptoms of dry eye syndrome are similar to those of other eye conditions. This is why it is important to confirm a diagnosis with a thorough eye examination. It may also be difficult to correctly identify the cause of dry eyes; you and your eye doctor will discuss additional tests in order to determine what underlying condition is causing your dry eye symptoms. For example, if rheumatoid arthritis is suspected, your eye doctor may order blood tests.
Dry Eye Tests
The Schirmer tear test may be used to diagnose dry eyes. Before the test begins, you will be asked to remove your contact lenses, if you wear them. As mentioned above, we produce two types of tears: basal tears and reflex tears.
Basal tears are always in your eyes and are composed of three layers: mucus, salty water, and oil. Reflex tears are the ones you produce when your eyes are irritated, such as when you cut an onion.
Newer methods for diagnosing dry eye are currently being developed. For example, one test looks for a particular molecule called lactoferrin. Several studies show that people with dry eye have low levels of this molecule.
Fluorescein eye drops may also be used to measure tear production. These special eye drops contain a dye that can be traced with a blue light as it is washed out of the eyes by the tears. The time it takes the colored tears to break up is referred to as “tear film breakup time.”
This method can detect any blocking, early evaporation of tears, or dehydrated spots on the cornea. The dye may also show up in the crevices between surface cells, and it can reveal ocular surface disease.
Dry Eye Treatment Options
Treatment for dry eyes may require treating an underlying condition. There are also certain medications, as well as surgical and non-surgical procedures that you and your doctor can discuss if you are dealing with Dry Eye Syndrome. Here are a few examples:
- Warm Moist Compresses: Not only is this relaxing, performed at least twice daily for five minutes this will promote a healthier tear flow and more lubricating tear production.
- OTC (over the counter) Lubrication: Also known as artificial tears, these work to supplement the body’s normal tear production.
- Silicone Plugs: This is a non-surgical procedure that involves plugging the upper and lower lids where tears drain into your nose. Tiny bits of silicone placed in these openings keep tears in your eyes and keep your eyes from drying out. These plugs can be temporary or permanent, depending on the severity of your symptoms, and the process is painless.
- Acrylic Plugs: This is a new type of punctual plug which turns into a soft gel when exposed to your body heat. It is a one-size-fits-all plug, so measurement is unnecessary. It works just the same as the silicone plugs.
- Hydrogel Plugs: This too is a new kind of punctual plug that expands into a soft, pliable gel when inserted into your tear-duct canal.
- Natural Supplements: Natural supplements such as flaxseed oil and Omega-3 are a great way to help you ease your dry eye symptoms. Fatty acids do this. Staying away from caffeine can also reduce your dry eye symptoms, since caffeine dehydrates your body.
- Some of the natural supplements you can find in your local store are TheraTears Nutrition, HydroEye, and Hydrate Essential.
- Surgery: Surgery is the last resort for those who cannot handle plugs inserted into their tear ducts. Instead, the tear ducts close with a minor procedure.
Other measures you can take include:
- Drink Water: Water is the best way to keep your body hydrated, especially if you live in dry, hot, or cold climates. And it’s usually free.
- Sunglasses: Wearing sunglasses outdoors can help the light sensitivity you may experience with dry eye. Wearing sunglasses can also help keep dust and debris out of your eyes on windy days.
- Clean More: Doing simple chores regularly, like dusting your living room and bedroom, can reduce the amount of pollutants in your home. Vacuuming regularly will also remove most of the dirt on your floor. Changing your air filters at least once a month can help to keep new pollutants from entering your home when you run your air conditioner or heater.
- Humidifiers: Running a humidifier in your home can increase the amount of moisture into the air, especially if you live in the desert. Humidifiers reduce symptoms of dry eye.
- Move to a New Location: Many adults live in residences where they have been for many years. But the environment you live in can play a crucial role in dealing with dry eyes. If possible, try moving to a location that is not dry, dusty, windy, or extremely hot or cold (see below—Top Dry Eye Cities in the US).
Dry Eye Medications
There are many dry eye medications on the market, most of which are eye drops. Many of the eye drops used to treat or prevent dry eyes can be purchased over the counter; others require a prescription.
If you believe your medication is causing your dry eye symptoms, talk with your eye doctor about switching. Never discontinue using medication unless directed to do so by your healthcare provider.
- Restasis: This is the only FDA-approved medication for Dry Eye Syndrome. The recommended dose is one drop, twice a day. This medicine is not intended for instant relief; rather, it is a long-term medication to assist the production of tears without the side effects of steroid-based eye drops.
- TheraTears: TheraTears brand includes a range of topical drops for dry eye, an omega-3 nutritional supplement for eye comfort, and a gentle and effective eyelid cleanser.
- HypoTears: HypoTears is an over-the-counter artificial tears product. It’s for temporary relief of burning and irritation due to dryness of the eye or exposure to wind or sun. It also helps protect against further eye irritation.
- AkwaTears: This product is used as a lubricant to prevent further irritation or to relieve dryness of the eyes.
- Bion Tears: Bion Tears is only available with a doctor’s prescription. It relieves dryness and irritation caused by reduced tear flow. It also helps prevent damage to the eye from certain eye diseases.
- Murine Tears: These lubricant eye drops soothe and lubricate dry, irritated eyes. This product contains six of the eleven major ingredients found in natural tears. It temporarily relieves burning and irritation due to dryness of the eye. At the same time, it protects against further irritation.
Gelling Agent Drops
- Systane: Systane is a brand that includes lubricant eye drops, nighttime lubricant eye drops, and preservative-free eye drops. It is for the temporary relief of burning and irritation due to dryness of the eye, and is available without a prescription.
- GenTeal: GenTeal lubricating eye drops with GenAqua are for moderate dry eye relief symptoms. This product is manufactured by CIBA.
- Blink Tears: This product reduces blurring, replenishes tear film each time you blink, and improves tear film stability.
These eye drops will replenish the lipid layer or tear film.
It is important to know that long-term use of steroid eye drops such as Alrex, Lotemax, FML, and Vexol can cause an elevation in eye pressure or the development of a cataract (clouding of the lens).
Serum Eye Drops
The use of serum eye drops alleviate dry eyes. Natural tears contain many growth factors like antibodies. Since these growth factors are present in human serum, using serum eye drops provides the surface-healing properties of natural tears.
Natural Dry Eye Treatment
Several nutritional and herbal supplements reduce symptoms of dry eye. Take a look at the chart below to learn more about various supplements:
|Supplement or Herb||Directions for Use||Comments|
|BioTears (biosyntrx)||Take two gel caps twice per day||Offers a complete formula for dry eye relief|
|Black currant seed oil||Take 3,000 mg daily before bed||Supplies essential fatty acids that promote circulation|
|Coenzyme Q10||Take 80 mg per day||A powerful antioxidant|
|Fish oil||Take 3 tbsp per day||High in vitamin A; re-moisturizes eye tissue|
|Vitamin A||Take 2,500 IU per day in tablet form or apply drops directly to the eye||Keeps eye tissues moisturized|
|Vitamin B6||Take 50 mg per day||Regulates kidney function|
|Vitamin C||Take 7,500 mg per day||A powerful antioxidant|
|Chamomile||Use warm as an infusion or cold as an eyewash||Offers support to the eye tissues|
|Goldenseal||Use warm as an infusion or cold as an eyewash||Offers support to the eye tissues; do not use during pregnancy; do not take internally for more than 1 week|
Chart courtesy of Dr. Jeffrey Anshel, Smart Medicine for Your Eyes, p213
Top Dry Eye Cities Across the U.S.
Dry-eye hot spots can aggravate your symptoms and make you miserable. If you are already having trouble keeping your eyes moist, or if you suffer from dry eye syndrome, you may want to stay away from some of the hottest, driest, windiest, and dustiest parts of the country.
At the very least, you should stock up on your artificial tears and lubricants before you go to any of these places on vacation or decide to pack up and move there.
The map below has been provided by the U.S. Drought Monitor (USDM):
According to the USDM, 73 percent of Texas experienced some of the driest conditions ever recorded during the first five months of 2015.
Not only does this directly affect millions of Texans with dry eye syndrome, but the drought is causing other environmental problems such as wildfires, wind, and dust—all of which can make dry eye symptoms much worse. Five of the ten driest cities in the US are in Texas.
Why is Dry Eye Syndrome Worse in These Cities?
There are numerous causes for Dry Eye Syndrome. Most people do not realize that their environment, particularly the city they live in, can be the major cause of their discomfort.
Living in the right part of the country, or even a different part of a city, can lessen your chances of getting dry eyes. It can also lessen your symptoms if you’ve already received a diagnosis of dry eyes.
Here’s a closer look at the major causes of this eye condition in these cities:
- Temperatures: Extreme hot or cold temperatures can cause significant damage to your eye. Both hot and cold temperatures cause dehydration.
- Humidity: Areas with little to no humidity can cause great discomfort if you suffer from dry eyes. Buying a humidifier will help the situation, but you can’t spend all your time in the house.
- Wind: Wind can kick up dust and dirt and whip them right into your eyes at any given moment. This causes irritation and makes you rub your eyes, which dries them out even more.
- Altitude: Higher altitudes are harder on the eyes due to the relative lack of oxygen. On the other hand, lower altitudes provide more oxygen, which keeps your eyes clear and moist.
- Pollutants: High levels of ozone and particulates can sting and scratch your eyes. Add a little bit of wind and you’ll be wishing for a new set of eyes. Pollutants like smoke, smog, and exhaust fumes can cause even more irritation and suffering.
- Ocular allergens: Allergens can cause extreme discomfort, itchiness, redness, swelling, and wateriness in your eyes. This will lead to constant rubbing or constant use of artificial tears or lubricants, which at that point isn’t any better than rubbing.
How Can I Prevent Dry Eyes?
Tears not only wash dust away from the eyes, but also soothe the eyes, provide oxygen and nutrients to the cornea, and help defend against eye infections by removing microorganisms that can colonize the eyes.
So how do we prevent dry eyes? In some cases it may not be that simple. As we age, our tear system, like the rest of our body, begins to shut down. We simply do not produce as many tears as we once did, and the tears we do produce are not of high quality. It is possible, however, for younger people to mitigate this condition by taking preventive steps now, before the tear system begins to shut down.
Here are some general tips to help you prevent dry eyes:
- Drink plenty of water each day to avoid dehydration.
- Avoid over-the-counter eye drops that contain preservatives.
- Increase your intake of vitamins A and C as well as important omega-3s by making sure your diet consists of many green, leafy vegetables, fish, nuts, citrus fruits, and vegetables.Staying away from foods and drinks that contain caffeine can also reduce your dry eye symptoms, as caffeine dehydrates your body.
- Do not ignore symptoms of dry eye syndrome.
- Avoid windy and dusty environments; do not allow air to blow directly into your eyes, as can happen when using a hair dryer.
- Use a humidifier during winter months, or whenever you are in a dry indoor environment.
- Take “eye breaks” if you are going to be reading or staring at a computer for a long time. Position computer screens below eye level to allow your eyelids to cover more of your eyes instead of keeping them wide open, as they are when you are looking up.
- Using warm, moist compress therapy on your eyes daily will help to keep the oily meibomian glands from becoming clogged.
- Practice good eyelid and eyelash hygiene. Use commercially available pre-moistened eyelid cleansers or a mild baby shampoo to keep your eyelashes and meibomian glands clean.
- Protect your eyes from UV rays, chemicals, radiation, and wind by wearing sunglasses, goggles, or a face mask.
Dry Eye Syndrome Facts and Statistics
Here are some interesting facts and statistics about dry eye syndrome:
- Dry eye syndrome is primarily a dysfunction of tears evaporating too quickly, as most dry eye sufferers still have normal reflex and emotional tearing.
- Approximately 33 million Americans suffer from dry eye syndrome.
- Approximately 89 percent of Americans are unfamiliar with the condition.
- Dry eye syndrome is the most common eye problem.
- Vitamin B3 may cause dry eyes.
- You blink an average of twenty times per minute.
- Almost 10 percent of post-menopausal women suffer from dry eyes.
- There is no cure for dry eye syndrome, only effective treatment options.
- Women are twice as likely as men to develop dry eyes.
- Estrogen supplements may increase the risk of dry eye by age 70.
- Estrogen and progesterone supplements together increase the risk of dry eye by 30 percent.
- Homeopathic remedies—which have never shown to treat any medical condition—may have a negative impact on eyes that are already dry
- Eye make-up can thin the oily layer of the tear film.
Talking to Your Eye Doctor About Dry Eyes
Here are some questions to ask your eye doctor about dry eyes:
- Which over-the-counter medications do you recommend to your patients and which ones do you not care for? Why?
- Do you think I would benefit more from prescription-strength dry-eye medication? Is there an over-the-counter eye drop that could replace the prescription one?
- How much do these types of drops cost? How often will I need to buy them?
- Which vitamins and nutrients should I increase my intake of?
- Based on the cause of my dry eyes, what treatment options do I have?
- How much does treatment cost? Does my insurance cover any of the costs?
- Can you describe the complications of dry eye to me?
- What are the side effects of the dry eye medication?
- What can I do at home and at work to prevent my eyes from drying out?