Dry eyes are caused by a variety of reasons that disrupt the healthy tear film. Understanding the underlying causes and risk factors can help you take preventive measures and seek appropriate treatment.
Primary Causes of Dry Eye
Also known as aqueous deficient dry eye or keratoconjunctivitis sicca, this occurs when your lacrimal glands don't produce enough of the watery component of tears.
Medical Conditions:
- Sjögren's syndrome (autoimmune disorder)
- Rheumatoid arthritis
- Lupus
- Scleroderma
- Graft vs. host disease
- Sarcoidosis
- Thyroid disorders
- Vitamin A deficiency
- Allergic eye disease
Medications:
- Antihistamines
- Decongestants
- Hormone replacement therapy
- Antidepressants
- Blood pressure medications
- Acne medications (isotretinoin)
- Birth control pills
- Parkinson's disease medications
Nerve Damage:
- Contact lens use (long-term)
- Corneal nerve damage
- Laser eye surgery (usually temporary)
Aging:
Tear production naturally decreases with age, making dry eye more common in people over 50.
Also known as evaporative dry eye, this is the most common type and occurs when tears evaporate too quickly due to problems with the oil layer of the tear film.
Meibomian Gland Dysfunction (MGD):
The oil glands along the edge of your eyelids become clogged or don't function properly. This is the leading cause of evaporative dry eye.
- More common in people with rosacea
- Associated with blepharitis (eyelid inflammation)
- Can be caused by seborrheic dermatitis
Reduced Blinking:
Blinking spreads tears evenly across your eye. Reduced blinking allows tears to evaporate.
- Parkinson's disease
- Concentrating on screens (reading, computer work, driving)
- Certain medications
Eyelid Problems:
- Ectropion (eyelids turn outward)
- Entropion (eyelids turn inward)
- Incomplete eyelid closure
Environmental Factors:
- Wind exposure
- Smoke (including secondhand smoke)
- Dry air (low humidity)
- High altitudes
- Air conditioning or heating
Other Causes:
- Eye allergies
- Preservatives in topical eye drops
- Vitamin A deficiency
Who is at Risk?
Certain factors make it more likely that you'll experience dry eyes:
Being older than 50. Tear production tends to diminish as you get older. Dry eyes are more common in people over 50.
Being a woman. A lack of tears is more common in women, especially if they experience hormonal changes due to pregnancy, using birth control pills, or menopause.
Eating a diet low in vitamin A (found in liver, carrots, and broccoli) or low in omega-3 fatty acids (found in fish, walnuts, and vegetable oils).
Wearing contact lenses or having a history of refractive surgery (LASIK, PRK).
Extended periods of screen use (computers, smartphones, tablets) which reduces blink rate.
Living or working in dry, windy, or air-conditioned environments. Exposure to smoke or air pollution.
While you can't always prevent dry eye disease, especially if it's related to aging or medical conditions, you can take steps to reduce your risk and minimize symptoms:
- Avoid air blowing directly in your eyes (fans, hair dryers, car heaters)
- Add moisture to the air with a humidifier
- Wear wraparound sunglasses or protective eyewear outdoors
- Take regular breaks during long tasks (follow the 20-20-20 rule)
- Position your computer screen below eye level
- Stop smoking and avoid secondhand smoke
- Use artificial tears regularly if you're prone to dry eyes
- Maintain a healthy diet rich in omega-3 fatty acids and vitamin A
- Stay hydrated by drinking plenty of water