What Is Dry Eye?
Dry eye means that your eyes don't have enough lubrication. Other terms for dry eye include dry eye syndrome, dry eye disease, and keratoconjunctivitis sicca.
For many people, it is a chronic condition. For others, it is a temporary symptom of contact use, eye surgery, certain medications, or environment.
Dry eyes can be the result of:
- A lack of tear production
- Poor quality of tears
11 Common Causes of Dry Eye
Several factors can influence your risk for dry eyes. Generally, women and people over 50 are more likely to develop dry eye syndrome.
The most common causes of dry eye include:
1. Older age
Your tear production declines with age.
In women, hormonal changes that occur with menopause negatively affect tear secretion. In men, a decline in androgen levels with age can cause a decrease in tear production.
2. Female gender
Menopausal and post-menopausal women have a higher risk of dry eyes.
3. Environment and climate
Sunny or windy conditions can trigger dry eyes. Pollution, pollen, dust, and other environmental irritants can also aggravate symptoms.
People living in dry climates are more prone to dry eye than those living in humid climates.
4. Contact lenses
Many people who wear contact lenses also suffer from dry eye.
Contact lenses:
- Affect the quality of your tear film
- Restrict oxygen and tear flow
- Can trap allergens and irritants in your eye
All of these factors can aggravate dry eyes.
5. Digital devices
Blinking helps your eyes distribute fresh tears.
However, most people who stare at a tablet, phone, or computer screen often do not blink frequently enough while using their device. This causes your eyes to dry out faster.
6. Medications
There are several classes of drugs that can cause dry eyes.
These include:
- Blood pressure medication
- Allergy (antihistamine) medication
- Antidepressants
- Antipsychotics
- Decongestants
- Hormonal therapies
- Diuretics
- Sedatives
- Retinoids (such as Accutane).
7. Eye surgery
Laser eye surgery (such as LASIK) and cataract surgery can disrupt the tear film. Post-surgical dry eye is common. Most cases are temporary; others are long-lasting.
8. Systemic conditions
Sjogren's Syndrome is an autoimmune disease that causes dry eyes and dry mouth.
Other conditions frequently associated with dry eye syndrome include:
- Rheumatoid arthritis
- Lupus
- Diabetes
- Thyroid problems
9. Blepharitis
Blepharitis is when your eyelids are swollen or red. It is usually caused by clogged oil glands.
10. Entropion
Entropion is a condition where your eyelid is turned inward. This causes your eyelashes to rub against your eyeball.
11. Ectropion
Ectropion is a condition where your eyelid turns outward. This leaves your eyes exposed and prone to irritation.
Why Are Tears Important?
A healthy tear film is important because your tears:
- Flush out irritants
- Prevent eye infections
- Help you see clearly
- Lubricate your eyes
Your tear film consists of three layers:
Mucin (mucous) layer
The first layer of your tear film (closest to your eye) is the mucous coating. It helps spread tears across your eye each time you blink. Goblet cells in your conjunctiva produce the mucin layer.
Aqueous (water) layer
The aqueous layer is the second and biggest layer of your tear film. This water layer helps moisturize your eyes and maintains clear vision.
The lacrimal glands, which sit behind the outer part of your eyebrow, produce the aqueous layer.
Lipid (oil) layer
The lipid is the outer layer of your tears. An oil layer is essential because it keeps the aqueous layer from evaporating quickly. The meibomian glands along your eyelid margins produce the oil.
Each time you blink, your eyelids help distribute a fresh layer of tears across your eye. If there is a deficiency in any of these tear film layers, you can have dry eyes.
Types and Symptoms of Dry Eye
Dry eye is categorized based on the affected tear film layer:
Aqueous deficient dry eye
This is when your lacrimal glands do not produce enough of the aqueous layer of tears. It's less common and usually affects people with underlying systemic conditions.
Evaporative dry eye
This occurs when you do not have a sufficient lipid layer in your tear film, causing the aqueous layer to evaporate. It's the most common type of dry eye and occurs when the meibomian (oil) glands are clogged.
People with rosacea are prone to evaporative dry eye.
Dry Eye Symptoms
Dry eye syndrome (chronic dry eye) affects a large percentage of the population. These percentages are likely to increase due to increased digital screen exposure. This can aggravate dry eyes.
Physical symptoms of dry eye syndrome include:
- Burning sensation
- Itching
- Heavy or sore eyes
- Foreign body sensation (feels like an eyelash is in your eye)
- Discharge
- Redness
- Tearing
- Eye pain
Visual symptoms of dry eye syndrome include:
How to Treat Dry Eye
There are a variety of treatments for dry eye, depending on the severity of the disease.
Some at-home therapies include:
Lubricating eye drops
Lubricating drops, also known as artificial tears, provide extra moisture for your eyes.
There are many over-the-counter options to choose from. Your eye doctor can recommend a specific type depending on the severity and type of dry eye you have.
Heat compresses
Heat compresses are helpful for clogged Meibomian glands. Clogged glands can lead to a deficiency in the lipid layer of your tear film. The heat, along with a gentle eyelid massage, encourages the oil glands to open up.
Your eye doctor can examine your eyes to check for clogged Meibomian glands.
Omega-3 fatty acid supplements
Omega-3 supplements such as fish oil or flaxseed oil have anti-inflammatory properties.
Since dry eye syndrome is considered an inflammatory condition, some research suggests taking omega-3 supplements may improve symptoms.
Humidifier
You can buy a humidifier (especially during winter) to help relieve dry eye symptoms.
Prescription medications or in-office treatments can also treat dry eye:
Meibomian gland expression
Your eye doctor can perform this procedure to unclog your oil glands if the heat compresses do not help.
Punctal plugs
Your eye doctor can place plugs into your puncta, the small holes in your eyelids that drain tears out of your eyes. The plug will slow down tear drainage, allowing more tears to stay on the surface of your eyes.
Temporary punctal plugs are made of collagen and dissolve after a few months. Semi-permanent plugs made of silicone are also available.
Corticosteroid eye drops
Corticosteroid eye drops are prescription anti-inflammatory drops that can improve dry eye symptoms.
Corticosteroids can increase your risk of cataracts and glaucoma. That's why most doctors only use this as a short-term treatment.
Immunomodulatory drugs
These medications change your body’s immune response.
Cyclosporine (brand name Restasis) and lifitegrast (brand name Xiidra) are two eye drop medications in this class of drugs. They work by reducing inflammation associated with dry eyes and stimulating your eyes to produce more tears.
Severe cases of dry eye may have to be treated with:
Autologous serum eye drops
These eye drops are made with your blood. The components of this serum are naturally found in your tears and promote healing.
Autologous serums are usually reserved for severe dry eye disease where the eye's surface is damaged.
Amniotic membranes
Amniotic membranes are made from the placental tissue of female donors after they give birth.
In a simple in-office procedure, your eye doctor places the membrane onto your cornea. The amniotic membrane serves as a biological bandage that promotes corneal healing and reduces inflammation.
Can Dry Eyes Cause Blindness, Headaches, or Floaters?
Dry eye rarely causes blindness. However, severe cases can cause significant pain and blurry vision.
Your cornea, the clear covering over your eye, is a delicate tissue filled with nerves. Good corneal health is essential for clear vision.
Severe dry eye syndrome can damage the cornea, which is why you have symptoms of pain and blurry vision. If left untreated, permanent scarring of the cornea and vision loss can occur.
Can Dry Eyes Cause Headaches?
The connection between dry eyes and migraines is unclear. However, people who get frequent migraines appear to develop dry eyes more often.
Can Dry Eyes Cause Floaters?
Dry eye is typically not a risk factor for floaters. Eye floaters are spots you see in your field of vision. They are common and usually harmless.
Some spots can move around, while other floaters appear stationary. Other people may see flashes of light instead of spots, which can look like someone is turning the light switch on and off.
