What causes dry eyes?

Environmental factors

Hot, dry and/or windy climates, High altitudes, Excessive sun exposure, Air-conditioning, Cigarette smoke, Air pollution, Air travel

Medications

Medications such as antihistamines for allergy, antidepressants, and certain types of blood pressure medications, medications for Parkinson’s disease, birth-control pills, sleeping pills, pain medications, and decongestants may attribute to dry eyes.

Contact lens wear

Two million individuals abandon soft contact lens wear altogether every year. Nearly 50% of these contact lens "dropouts" attribute dryness and discomfort as the primary reasons.

Systemic diseases

The glands that are producing tears for the eye can be attacked in Parkinson's disease, diabetes and auto-immune diseases like Rheumatoid arthritis, etc.

Refractive eye surgeries

Dry eye is the most common complaint or adverse event after LASIK.

Hormonal deficiencies or changes

Thyroid conditions and hormonal changes during menopause are also the common factors that are associated with dry eyes.

Low blink rate

Blinking is critical in spreading the tear film over the surface of the eye and stimulating tear production. A chronic low blink rate is associated with dry eye symptoms. Computer use, reading, and watching TV are the three activities most commonly associated with a low blink rate.

Dirty and oily eyelids

Oil from the eyelids can spill onto the surface of the eye and disrupt the composition of the tear film hence giving rise to dry eye symptoms. Dirty and oily eyelids usually appear red and burning sensation may be felt on the eye.

View animation here