Causes of Dry Eye

An overview of known and suspected causes of "dry eye", from aging, disease and medical treatments to environmental factors
 

Mild to moderate dry eye is most frequently associated with aging (particularly peri or postmenopausal women), contact lens wear, and computer use.

Moderate to severe dry eye is often associated with Sjogren's syndrome (an auto-immune disease which causes dry eyes, nose and mouth) and LASIK vision correction surgery.

Aging

Aging is directly associated with a reduction in lipid production, resulting in evaporative dry eye.

Climate and other environmental factors

Outdoors and indoors, humidity levels, wind, and presence of irritants can contribute to dry eye symptoms:

• Hot, dry and/or windy climates
• High altitudes
• Excessive sun exposure
• Central heating
• Air conditioning
• Hair dryers
• Cigarette smoke
• Air pollution
• Air travel

Contact lens wear

Dry eye is the most common complaint amongst contact lens wearers.

Contact lenses absorb the tear film, and rub against the conjunctiva in the eyelids, which may cause or exacerbate dry eye. Long-term contact lens wear may decrease epithelial nerve sensation, which would reduce the stimulus to produce more tears.

Diseases

• Parkinson's disease
• Sjogren's syndrome (an auto-immune disease with
• Auto-immune diseases (lupus, rheumatoid arthritis, Sjogren's)
• Rheumatoid arthritis
• Lupus
• Lacrimal gland deficiency
• Diabetes
• Sarcoidosis
• Stevens-Johnson syndrome
• Rosacea: Facial rosacea is commonly associated with ocular rosacea, which causes conditions such as blepharitis
• See also section on eyelid conditions.

Eye injuries, eye surgeries

• Chemical burns
• Laser refractive surgery, e.g. LASIK, PRK, LASEK, epi LASIK, etc. LASIK is best known for dry eye because it severs or ablates more nerves than any other refractive surgery.
• Corneal transplants

Eyelid conditions or anatomical features

• Lagophthalmos: Incomplete closure of the lids (may be natural, may be caused by hypothyroidism, LASIK, blepharoplasty, or other factors)
• Droopy eyelid
• Bulging eye
• Proptosis
• Ectropion
• Entropion
• Nocturnal lagophthalmos
• Bell's palsy
• Pterygium/Pingecula
• Conjunctivalchalsis

Eye diseases affecting the meibomian glands

• Blepharitis
• Ocular rosacea (thought to be present in up to 75% of perimenopausal women with facial rosacea)
• Meibomian gland dysfunction (also called meibomitis or meibomianitis)

Hormonal deficiencies or changes

• Thyroid conditions
• Hormonal changes during menopause
• Decreased production of androgen
• Estrogen supplementation (there are reports both of this improving dry eye conditions and worsening them!)

Low blink rate

Blinking is a critical function in spreading tears over the eye surfaces and stimulating tear production. A chronic low blink rate is associated with dry eye symptoms.

Whenever focus on an object near at hand on a sustained basis, you are probably blinking much less frequently. Computer use, reading, and watching TV are the three activities most commonly associated with a low blink rate. Computer use is believed to reduce the blink rate from 22 per minute to 7 per minute.

Medications

Many medications can cause or exacerbate dry eye symptoms. If a medication you are using seems to be making your eyes worse, read up on side effects at sources like Drugs.com and discuss options with your doctor - s/he may be able to prescribe an alternative medication with a better side effect profile. Use common sense though - don't stop taking a medication without consulting your doctor!

• Allergy medications, esp. antihistamines
• Antidepressants (e.g. amitriptyline, diazepam)
• Some blood pressure medications
• Parkinson's medications
• Birth control pills
• Diuretics
• Beta blockers
• Sleeping pills
• Many pain medications
• Certain medications which regulate heart rhythm irregularities
• Decongestants

Radiation therapy

Smoking

Vitamin A deficiency