What Causes Dry Eyes? Understanding the Common Causes and Treatments

Dry eyes, also known as dry eye disease, are a common condition affecting many people, especially as they age. It occurs when the eyes do not produce enough tears or when the tear film on the surface of the eye’s surface breaks down. This can lead to irritation, discomfort, and even blurred vision. The condition can significantly impact daily life, making it difficult to perform simple tasks such as reading, using a computer screen, or wearing contact lenses. This article will explore the various causes of dry eyes, how they affect tear production, and the available treatments for managing this condition.

What Is Dry Eye Disease?

Dry eye disease occurs when the eyes are not adequately lubricated, resulting in dryness, irritation, and a gritty feeling. The condition can be due to either a reduction in tear production or increased tear evaporation. Tears are essential for maintaining a healthy tear film, which consists of three layers: the watery layer, the oily layer, and the mucous layer. These layers work together to keep the eyes lubricated, protect the eye’s surface, and provide nutrients to the cornea.

When the balance of these layers is disrupted, either through fewer tears being produced or the tears evaporating too quickly, dry eye symptoms such as discomfort, redness, and blurry vision can result.

Causes of Dry Eyes

Numerous factors can lead to dry eyes, including environmental factors, lifestyle habits, underlying medical conditions, and even certain medications. Below are some of the most common causes of dry eyes.

1. Aqueous Tear Deficiency

The most common cause of dry eyes is aqueous tear deficiency, where the lacrimal glands (tear glands) fail to produce enough tears. The lacrimal glands produce the watery layer of the tear film. When these glands do not function properly, insufficient moisture keeps the eyes lubricated, leading to dryness and discomfort.

This condition can be caused by factors such as age, hormonal changes, and medical conditions like Sjogren’s syndrome—an autoimmune disorder in which the body attacks the lacrimal glands. Hormonal changes, such as those caused by birth control pills or hormone replacement therapy, can also contribute to reduced tear production in both men and women.

2. Meibomian Gland Dysfunction (MGD)

The meibomian glands are responsible for producing the oily layer of the tear film, which prevents tears from evaporating too quickly. Meibomian gland dysfunction (MGD) occurs when these glands become blocked or do not function properly, leading to an unstable tear film and increased tear evaporation. This can cause symptoms such as dryness, burning eyes, and a gritty feeling.

MGD is often seen in individuals with chronic dry eyes and is more common in people who use contact lenses regularly or suffer from conditions like rosacea. Poor eyelid hygiene and environmental factors such as exposure to cigarette smoke or dry environments can exacerbate MGD.

3. Environmental Factors

Environmental factors can play a significant role in developing dry eye symptoms. Prolonged exposure to dry air, wind, dust, or secondhand smoke can cause tear evaporation, drying the eyes out. For instance, people living in smoky environments or spending long hours in air-conditioned rooms may experience increased tear evaporation.

In addition, computer screen use has become one of the major causes of dry eyes in recent years. Staring at a screen for extended periods decreases the frequency of blinking, which helps to spread tears over the surface of the eyes. This can result in eye dryness and other related symptoms.

4. Contact Lenses

Contact lenses can contribute to dry eyes, especially if worn for long periods or in a dry environment. They reduce the natural oxygen supply to the eye’s surface, which can cause irritation and tear instability. Additionally, contacts can absorb moisture from the tear film, leading to tear evaporation and dryness. Certain lenses, such as soft contact lenses, may exacerbate this issue more than others.

Patients who wear contacts may experience painful eyes or a gritty feeling when their eyes produce fewer tears or when the tear film becomes unstable due to tear evaporation.

5. Medications

Certain medications can cause dry eyes as a side effect. Common medications contributing to dry eye symptoms include antihistamines, decongestants, antidepressants, and blood pressure medications. These drugs can reduce tear production or increase tear evaporation, leading to dryness and discomfort. For example, birth control pills and hormone replacement therapy can alter hormone levels and affect tear production.

Additionally, medications for conditions such as rheumatoid arthritis, high blood pressure, and depression can interfere with the natural balance of tears, causing dryness and discomfort.

6. Autoimmune Diseases

Autoimmune diseases like Sjogren’s syndrome and rheumatoid arthritis can interfere with tear production by attacking the tear glands. In Sjogren’s syndrome, the immune system mistakenly targets the lacrimal glands, leading to aqueous tear deficiency. This results in dry eyes and other symptoms, such as dry mouth. Rheumatoid arthritis and other inflammatory conditions can also impact the tear glands and tear production, contributing to dry eye symptoms.

7. Age

Tear production naturally decreases as we age, and the tear glands may become less efficient. This results in fewer tears being produced to keep the eyes lubricated. Age-related dry eyes are particularly common in older adults. They may be exacerbated by factors like hormonal changes (particularly in women after menopause) and the use of medications that affect tear production.

8. Eye Diseases and Infections

Certain eye diseases and infections can also lead to dry eyes. Conditions like blepharitis (inflammation of the eyelid) and conjunctivitis (pink eye) can interfere with the normal function of the tear glands and tear ducts. These infections can disrupt the balance of the tear film, leading to symptoms such as watery eyes, burning, and blurred vision.

9. Nasal Spray and Other Medications

Using nasal sprays, particularly those that contain antihistamines or decongestants, can contribute to dry eyes. These sprays work by constricting blood vessels in the nasal passages, but they can also reduce the natural moisture in the eyes, leading to tear evaporation. Similarly, anti-inflammatory medications, especially those used to treat conditions like rheumatoid arthritis, can interfere with tear production.

Treatment Options for Dry Eyes

If you experience dry eye symptoms, various treatments are available to help alleviate discomfort and restore normal tear production.

1. Artificial Tears

Artificial tears are the most common treatment for dry eyes. They are available over-the-counter as eye drops. These drops mimic the function of natural tears and help to lubricate the eye’s surface. There are many different types of artificial tears, some of which contain preservatives and others that are preservative-free. It’s important to choose the right type for your specific needs.

Preservative-free artificial tears may be recommended for individuals with more severe dry eye disease, as preservatives can sometimes cause irritation over time.

2. Warm Compresses and Lid Hygiene

Warm compresses can help stimulate tear production and improve the function of the meibomian glands, which produce the oily layer of the tear film. Lid hygiene is also important for managing meibomian gland dysfunction (MGD). Regular cleaning of the eyelids with a mild cleanser can help remove debris and improve tear stability.

3. Prescription Medications

For more severe cases of dry eye disease, prescription medications may be necessary. These may include:

• Anti-inflammatory eye drops, such as cyclosporine A (Restasis), help increase tear production.
• Lifitegrast (Xiidra), another eye drop medication that works by reducing inflammation in the eye.
• Corticosteroid eye drops (used only for short periods) to reduce inflammation.

4. Punctal Occlusion

In cases where tear production is insufficient, punctal occlusion can prevent the tears from draining too quickly. This procedure involves the insertion of small plugs into the tear ducts to block the tear drain, allowing tears to remain on the eye’s surface longer.

5. Lifestyle Adjustments

Making certain lifestyle changes can also help alleviate dry eye symptoms. These include:

• Avoiding smoke and environmental irritants
• Taking frequent breaks when working with computer screens to reduce eye strain
• Using a humidifier to add moisture to the air, especially in dry environments
• Wearing protective eyewear such as goggles in windy or dry environments

Conclusion

Understanding the causes of dry eyes and recognizing the symptoms of dry eyes is crucial for finding the right treatment. Whether it’s insufficient tear production, evaporation, or underlying medical conditions, dry eye disease can significantly affect your quality of life. Treatment options range from artificial tears and warm compresses to more advanced treatments like punctal occlusion and prescription medications. If you’re experiencing persistent dry eyes, it’s important to consult an ophthalmologist at Dr Anton van Heerden clinic in Melbourne for a proper diagnosis and treatment plan tailored to your specific needs.

References

https://my.clevelandclinic.org/health/diseases/24479-dry-eye

https://www.mayoclinic.org/diseases-conditions/dry-eyes/symptoms-causes/syc-20371863

https://www.nhs.uk/conditions/dry-eyes/#:~:text=Causes%20of%20dry%20eyes&text=you%20wear%20contact%20lenses,it’s%20windy%2C%20dry%20or%20dusty