Dry eyes occur when your tears aren't able to provide adequate moisture for your eyes. Tears can be inadequate for many reasons. For example, dry eyes may occur if you don't produce enough tears or if you produce poor-quality tears.
Dry eyes feel uncomfortable. If you have dry eyes, your eyes may sting or burn. You may experience dry eyes in certain situations, such as on an airplane, in an air-conditioned room or after looking at a computer screen for a few hours.
Dry eyes treatments may make you more comfortable. Dry eyes treatments can include lifestyle changes and eyedrops. For more serious cases of dry eyes, surgery may be an option.

Symptoms
Signs and symptoms of dry eyes, which usually affect both eyes, may include:

When to see a doctor
See your doctor if you've had prolonged signs and symptoms of dry eyes, including red, irritated, tired or painful eyes.

Dry Eyes

The tear glands (lacrimal glands), located above each eyeball, continuously supply tear fluid that's wiped across the surface of your eye each time you blink your eyelids. Excess fluid drains through the tear ducts into the nose.

Dry eyes are caused by a lack of adequate tears. Your tears are a complex mixture of water, fatty oils, proteins and electrolytes. This mixture helps make the surface of your eyes smooth and clear, and it helps protect your eyes from infection.

For some people, the cause of dry eyes is an imbalance in the composition of their tears. Other people don't produce enough tears to keep their eyes comfortably lubricated. Eyelid problems, medications and other causes, such as environmental factors, also can lead to dry eyes.

Poor tear quality
The tear film has three basic layers: oil, water and mucus. Problems with any of these layers can cause dry eyes symptoms.

Decreased tear production
Dry eyes can occur when you're unable to produce enough tears. The medical term for this condition is keratoconjunctivitis sicca (ker-uh-to-kun-junk-ti-VIE-tis sik-uh).
You may not produce enough tears if you:

Eyelid problems
Blinking spreads a continuous thin film of tears across the surface of your eyes. If you have an eyelid problem that makes it difficult to blink, tears may not be spread across your eye adequately or your tears may evaporate too quickly, causing dry eyes. Eyelid problems can include an out-turning of the lids (ectropion) or an in-turning of the lids (entropion).
Medications that cause dry eyes
Medications that can cause dry eyes include:

Other dry eyes causes
Other causes of dry eyes include:

Risk factors
Factors that make it more likely that you'll experience dry eyes include: Complications
Most people don't experience complications caused by dry eyes. Complications that can occur include: