Millions of Americans of all ages suffer from allergies. There are allergies to the environment, such as hay fever, pollens, grasses, etc. There are also specific allergies to certain chemicals.

Since the eyes are exposed to the environment, and have a "sticky surface" because they are moist, they are prone to easy challenge by irritants. The tear film helps wash away these irritants. In some people, even brief exposure to an allergen (anything that causes allergy symptoms) will cause symptoms.

There are new classes of medications available, so that ineffective or more dangerous medications are no longer needed. The new medicines work to stabilize the ocular surface which can release histamine and similar chemicals. The chemicals cause itching, stinging, redness, and tearing. Similarly, simple mechanical rubbing of the eye can cause release of these chemicals and chemical stimulants. This is why itching is rarely relieved for long by eye rubbing.

Treatment for allergic eye disease rarely includes allergy scratch testing or searches for specific allergens. Severe cases might require this, and might actually require special air filters in the home and other environments.

Usually, prescription drops work short- and long-term and may be used as little as twice a day, and are administered for periods lasting weeks to months. Some patients use the drops all year round; some will just use them from the spring through the fall.

Anti-allergy prescription eyedrops, developed in the past three or four years, have allowed some patients to actually enjoy mowing their lawn for the first time in decades. However, allergic eye disease requires diagnosis and management and prescription treatment by an eye care professional. Distinguishing this condition from infection, dry eye, and other more complicated conditions requires a proper microscopic examination (the use of the slit lamp biomicroscope).