The diagnosis and ongoing management of dry eyes can be very challenging.

Dry eyes can be tearing frequently, but they might be dry! At first look, this might seem strange. However, if eyes are irritated because of excessive dryness, they will stimulate "reflex" tearing. The tearing is insufficient to relieve irritation so the eye feels dry, scratchy, irritated, or appears red.

The tear film is composed of three elements: oil, water, and mucus. Oil is secreted by glands in the eyelid, water is pumped onto the eye by a lacrimal gland, and mucus is made by mucus membranes. This might seem to be more detailed than the average patient would want to know. However, this practical approach customizes treatment to the tear deficiency.

Many will have "primary" dry eyes. This means that they are making an insufficient quantity of the water component. Most helpful is frequent artificial tears. Avoiding drafts and dust can help. In winter, homes are heated, dry, and whole-house humidifiers do not do much to improve moisture in the air. In summer, air conditioning reduces humidity too.

Dry eyes are more prone to being irritated by chemicals and pollutants, etc, because there is not that much tear flow to wash away irritants. Thus, irritants have more time in contact with delicate eye tissues. Contact lens wearers, especially must have generous tear films.

Essentially, oil and water do not mix well even on the eye. The relative components must be carefully balanced for best comfort and best vision.

The most common dry eye treatment for the problems of decreased "water" is frequent artificial tears, over the counter available. Some artificial tear brands are "non-preserved" and avoiding preservatives can be helpful for some patients, particularly those who must put the tear drops in very often.