What causes dry eye?
At one time or another, many of us have experienced dry eyes — that itchy, irritating sensation that makes us want to rub our eyes. Some people also report a gritty sensation, or a feeling that something is present in the eye. Other dry eye symptoms may include appearing red or swollen, and sore, burning, or aching eyes. The eyes may also be sensitive to light, produce blurred vision, or feel heavy or tired.
If you experience these symptoms on a consistent basis, you may have dry eye syndrome, which is simply chronic dry eye. This can cause complications like eye infections or damage to the surface of the eye, so it is important to address it if this is the case.
Dry eye causes
To better understand dry eye and its causes, it’s important to learn about tears.
Tears are the eye’s lubrication, but they are made of more than just water. They are a mixture of fatty oils, mucus, and water that helps lubricate the surface of the eyes and protect them from infection.
When there isn’t enough lubrication, or the right mix of lubrication, the result is dry eye.
Some common causes of dry eye include:
Decreased tear production - Some people do not naturally produce enough tears. This can be caused by:
- Certain medical conditions such as diabetes, rheumatoid arthritis, lupus, thyroid disorders, and vitamin A deficiency
- Certain medications, including cold and allergy medicines, birth control, antidepressants, drugs for high blood pressure, and hormone replacement therapy
- Complications from LASIK surgery
- Damage to the tear glands
Increased tear evaporation – Tears are made of more than water. If one or more of the ingredients is missing or low, tears can evaporate more quickly, making them less effective. Common causes of tear evaporation could be:
- Exposure to smoke, dry air, or wind
- Blinking less often, which often occurs when reading, working on a computer, or driving long distances
- Eyelid problems, such as eyelids that naturally turn outward or inward
Imbalanced tear composition – If the balance of ingredients in your tears is off, it can make them work less effectively. This can happen for several reasons. For example, the glands that produce the oils needed for healthy tears can become blocked, making tears too watery and less effective.
Reflex tearing – Strangely, if your eyes become too dry, your body may try to compensate by creating more tears. Unfortunately, these tears are mostly water, so they don’t provide the lubrication and protection they should.
Dry eye treatment options
Over-the-counter eye drops will usually relieve mild dry eye. Drops, gels, gel inserts, and ointments are all types of artificial tears used to help lubricate the eyes.
Things to consider with over-the-counter medications:
- Be aware of products that use preservatives to prolong shelf life. The preservatives can irritate eyes if used too often, so these drops should not be used more than four times a day. Preservative-free drops come in single-use vials and are better for people who need to apply them more often.
- Ointments can provide longer-lasting relief, but because they are thicker, they make your vision cloudy temporarily, so it’s best to use them before bed.
- Avoid prolonged use of drops that claim to reduce redness.
Home remedies like frequently washing your eyelids with mild soap and warm water, or rubbing gently with warm compresses can help.
If your symptoms are more serious, or can’t be easily relieved, you may require the help of an eye specialist. To learn the difference between the two types of eye specialists, see the article Optometrist vs. ophthalmologist: What’s the difference?
To help provide more permanent relief, your doctor will first want to determine the cause of your dry eye. This may include in-office tests to determine the quantity and quality of your tears.
If your current medications are not the cause, or can’t be changed, there are other medicines that can be used to help with tear production and quality.
How to help yourself
Whether dry eye happens from time to time or is chronic, there are things you can do to help improve your symptoms.
- Pay attention to your surroundings – Avoid situations where air is blown about with fans, air conditioners, heaters, or blow dryers. Spending time in dry, windy locations or at high altitudes will make tears evaporate quicker. Consider using wraparound sunglasses or eye shields. You should also avoid smoke.
- Take breaks to rest your eyes – When you stare at something for a long time without blinking, you aren’t lubricating your eyes. Try to be aware of this and blink more often. Closing your eyes for a few moments can also help.
- Reposition your screen - If you work on a computer, position the screen to just below eye level. This can help slow the evaporation of tears because you won’t have to keep your eyes open as wide.
- Use artificial tears – If you tend to get dry eye or have chronic dry eye, using eye drops at regular intervals will keep your eyes lubricated.
- Add moisture to indoor air – A basic humidifier can provide some relief.
If it is temporary and mild, dry eye can usually be treated at home. However, if you are having difficulty getting relief, it may be time to consult an eye care specialist.
Helpful medications for dry eye
If it becomes necessary to see a specialist, there are several options that can be used to relieve your symptoms, depending on what is causing dry eye. For example:
- Antibiotics can be used to reduce inflammation of your eyelids.
- If the surface of your eyes (corneas) are dry, prescription eye drops can be used.
- For more severe cases of dry eye, eye inserts may be used to slowly release lubrication.
- Tear-stimulating drugs, in drop or pill form, can be used to help increase tear production.
Addressing dry eye syndrome
If these medications don’t work, or your symptoms are more severe, you may be suffering from dry eye syndrome. In those cases, there are a few procedures a doctor can perform that may resolve the problem.
- Closing tear ducts – In some cases, tears drain away from the eyes too quickly. Tiny tear duct plugs can be inserted to help partially or completely close the tear ducts. These plugs can be removed. Tear ducts can also be cauterized, or heated until they collapse, permanently sealing them.
- Opening oil glands – If oil glands are blocked, a treatment that warms and massages the eyelids may help clear any blockages.
- Light therapy and eyelid massage – Depending on the cause of dry eye, a combination of light therapy and eyelid massage may help.
- Contact lenses for dry eye – A new type of contact lens that helps protect the surface of the eyes while trapping moisture may work for some people.
Dry eye is a common occurrence for many people. Often it is a temporary condition that can be relieved by making simple adjustments such as taking breaks or using eye drops. In those cases where the condition is more severe or long-lasting, consulting an eye care specialist can help.