Tears are needed to lubricate the eyes and to wash away particles and foreign objects. A healthy tear film on the eye is necessary for good vision.

Dry eyes develop when the eye is unable to maintain a healthy coating of tears

Keratitis sicca; Xerophthalmia; Keratoconjunctivitis sicca

Dry eye usually occurs in people who are otherwise healthy. It becomes more common with age. This can occur due to hormonal changes that make your eyes produce fewer tears.

Other common causes of dry eyes include:

• Dry environment or workplace (wind, air conditioning)
• Sun exposure
• Smoking or second-hand smoke exposure
• Cold or allergy medicines

Dry eye can also be caused by:

• Heat or chemical burns
• Previous eye surgery
• A rare autoimmune disorder in which the glands that produce tears are destroyed (Sjogren syndrome)

Symptoms may include:

• Blurred vision
• Burning, itching, or redness in the eye
• Gritty or scratchy feeling in the eye
• Sensitivity to light

Tests may include:

• Visual acuity measurement
• Slit lamp exam
• Diagnostic staining of the cornea and tear film
• Measurement of tear film break-up time (TBUT)
• Measurement of rate of tear production (Schirmer's test)
• Measurement of concentration of tears (osmolalilty)

The first step in treatment is artificial tears. These come as preserved (screw cap bottle) and unpreserved (twist open vial). Preserved tears are more bottle) convenient, but some people are sensitive to preservatives. There are many brands available without a prescription.

Start using the drops at least 2-4 times per day. If your symptoms are not better after a couple of weeks of regular use:

• Increase use (up to every 2 hours)
• Try a different brand
• Talk to your health care provider if you can’t find a brand that works for you

Other medical treatments may include:

• Fish oil 2-3 times per day
• Glasses, goggles or contact lenses that keep moisture in the eyes
• Medicines such as Restasis, topical corticosteroids, and oral tetracycline and doxycycline
• Tiny plugs placed in the tear drainage ducts to moisture stay on the surface of the eye longer

Other helpful steps include:

• Don't smoke and avoid second-hand smoke, direct wind, and air conditioning.
• Use a humidifier, especially in the winter.
• Limit allergy and cold medicines that may dry you out and worsen your symptoms.
• Purposefully blink more often. Rest your eyes once in a while. 
• Clean eyelashes regularly and apply and warm compresses.

Some dry eye symptoms are due to sleeping with the eyes slightly open. Lubricating ointments work best for this problem. You should use them only in small amounts since they can blur your vision. It is best to use them before sleep.

Surgery may be helpful if symptoms are because the eyelids are in an abnormal position.

Most people with dry eye have only discomfort, and no vision loss.

In severe cases, the clear covering on the eye (cornea) may be come damaged or infected.

Call health care provider immediately if:

• You have red or painful eyes.
• You have flaking, discharge, or a sore on your eye or eyelid.
• You have had an injury to your eye, or if you have a bulging eye or a drooping eyelid.
• You have joint pain, swelling, or stiffness and a dry mouth along with dry eye symptoms.
• Your eyes do not get better with self-care within a few days. 

Stay away from dry environments and things that irritate your eyes to help prevent symptoms.

Lemp MA, Foulhs GN. The Diagnosis and Management of Dry Eye Disease. In: Tasman W, Jaeger EA, eds. Duane’s Ophthalmology. 2012 ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2012:vol 4; chap 14.

Peters E, Colby K. The Tear Film. In: Tasman W, Jaeger EA, eds. Foundations of Clinical Ophthalmology. 2012 ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2012:vol 2; chap 3.