Environmental Factors

Many people experience dry eyes as a result of certain climate factors such as high altitude, dry air, wind or even the sun. Other environmental factors such as smoke, dust, mold or animal dander can stir up allergies that often cause dry eyes.

Medications

Dry eyes are a common side effect of certain medications. Birth control pills, sleeping pills, antihistamines and decongestants, morphine and certain antidepressants can all be the cause of dry eyes.

Diseases

Dry eyes are often one of the symptoms of certain diseases. Sjogren's syndrome, rheumatoid arthritis and collagen vascular diseases all cause a decrease in tear production.

Surgery

Surgery on the cornea can cause dry eyes. Lasik surgery is one of the most common types of corneal surgery. Radiation treatment can also cause dry eyes.

Eye Problems

Dry eyes are often a result of another problem with the eyes. For example, if there is a structural problem with the eye that could keep the lid from closing properly, this will cause the eye to dry out. A problem with the tear ducts can also result in dry eyes.

Aging

While most people hate to hear it, sometimes dry eyes are simply a result of aging. Women may experience dry eyes when they are going through menopause.

Source:

Medicine Net: Dry Eyes

Dry Eye Pain

Mayo Clinic: Dry Eyes