Encyclopedia - Allergies of the Eye

What causes eye allergies?
How do you protect your eyes from allergies?

Allergies occur when the body overreacts to often-harmless substances in the environment. Triggered by the body's immune system, allergies protect eyes from injury. Because the eye is an exposed area of the body, foreign particles such as pollen, animal dander, and mold spores can adhere to the moist ocular surface and cause the same types of allergic reactions as generated when the particles reach the nose, throat, or lungs.

Although people with eye allergies often have hay fever or other allergic problems, sometimes the eye reaction can come as a complete surprise. Visible symptoms of eye allergies may include swelling, hives, itching, watering, redness, eye pain, and sensitivity to light. Symptoms of eye allergies are similar to symptoms of infectious diseases of the eyes, so diagnosing and treating ophthalmic allergic conditions can be a challenge.

What causes eye allergies?

Allergic reactions in the eyes, or ocular allergies, can be caused by airborne particles such as pollen, animal dander, dust, or molds. Eye allergies can be seasonal, or they may be perennial, affecting sufferers unpredictably throughout the year. Bacteria, food sensitivities, cosmetics, fabrics, soaps, and other substances may cause year-round allergies. Plant pollens and molds are the most common causes for chronic seasonal allergies. People who wear contact lenses can have ocular allergies to contact lens solutions as well as to the environment.

Airborne allergens can readily reach the conjunctiva, which is the thin, transparent membrane that lines the inner surface of the eyelid and covers the sclera where it becomes the white of the eye (See Anatomy of the Eye). Systemic allergies can affect other ophthalmic tissues.

How do you protect your eyes from allergies?

The best way to protect your eyes from allergies is to avoid allergens completely. Some of the most common ones are cigarette smoke, cat dander, smog, some houseplants, and petroleum solvents. It's important to determine the cause of allergies where possible. An allergist can administer a comprehensive battery of diagnostic tests.

You can apply ice packs and cold compresses over your eyes to provide relief from allergic reactions, thereby reducing puffiness and itching. Using a tear substitute helps to remove and dilute allergens, and you can use ointments and time-released tear replacements at night to moisturize the ocular surface. Applying a topical antihistamine reduces eye redness and itching. Mild topical steroids, which should only be used under a doctor's supervision, can treat acute or chronic cases. Eyeglasses and facial hair can collect allergens, so clean them frequently. A facemask can often provide relief when you are outside, while special air filters, either freestanding or furnace-mounted, can minimize the allergens in the air inside your home.

Many allergies are seasonal, and the symptoms disappear for periods of time. However, every time your eye is inflamed, it never completely recovers. Allergies of the eye should be taken seriously and treated by an eye doctor to prevent more serious consequences.