Eye allergies often are hereditary, and occur due to processes associated with other types of allergic responses.
When an allergic reaction takes place, your eyes may be overreacting to a substance perceived as harmful, even though it may not be. For example, dust that is harmless to most people can cause excessive production of tears and mucus in eyes of overly sensitive, allergic individuals.
Allergies can trigger other problems, such as conjunctivitis (pink eye) and asthma. Combined nasal and eye allergies create a condition known as rhinoconjunctivitis.
About 30 percent to 50 percent of U.S. residents have allergy symptoms. And about 75 percent of those symptoms affect the eyes.
Allergy Symptoms and Signs
Common signs of allergies include:
- Red, swollen or itchy eyes
- Runny nose
- Sneezing and coughing
- Itchy nose, mouth or throat
- Headache from sinus congestion
Beyond more obvious symptoms, you also may feel fatigued and could suffer from lack of sleep.
What Causes Eye Allergies?
Many allergens are in the air, where they come in contact with your eyes and nose. Airborne allergens include pollen, mold, dust and pet dander.
Other causes of allergies, such as certain foods or bee stings, do not typically affect the eyes the way airborne allergens do. Adverse reactions to certain cosmetics or drugs such as antibiotic eye drops also may cause eye allergies.
Some people actually are allergic to the preservatives in eye drops such as those used to lubricate dry eyes. In this case, you may need to use a preservative-free brand.
General Eye Allergy Treatment
Avoidance. The most common "treatment" is to avoid what's causing your eye allergy. Itchy eyes? Keep your home free of pet dander and dust and keep pets off the furniture. Stay inside with the air conditioner on when a lot of pollen is in the air. Air conditioners filter out allergens, though you must clean the filters from time to time.
Make sure you wear wraparound sunglasses to help shield your eyes from allergens, and drive with the windows closed.
Medications. If you're not sure what's causing your eye allergies, or you're not having any luck avoiding them, your next step probably will be medication to alleviate the symptoms.
Over-the-counter and prescription medications each have their advantages; for example, over-the-counter products are often less expensive, while prescription ones are often stronger.
Eye drops are available as simple eye washes, or they may have one or more active ingredients such as antihistamines, decongestants or mast cell stabilizers that inhibit inflammation. Antihistamines relieve many symptoms caused by airborne allergens, such as itchy, watery eyes, runny nose and sneezing. Decongestants help shrink swollen nasal passages for easier breathing.
Relief for Watery, Itchy Eyes
Common causes of excessively watery eyes are allergies and dry eye syndrome — two very different problems.
With allergies, your body's release of histamine causes your eyes to water, just as it may cause your nose to run. It may seem illogical that watery eyes would result from dry eye syndrome. But this is sometimes true, because the excessive dryness works to overstimulate production of the watery component of your eye's tears.
Decongestants clear up redness. They contain vasoconstrictors, which simply make the blood vessels in your eyes smaller, lessening the apparent redness. They treat the symptom, not the cause.
In fact, with extended use, the blood vessels can become dependent on the vasoconstrictor to stay small. When you discontinue the eye drops, the vessels actually get bigger than they were in the beginning. This process is called rebound hyperemia, and the result is that your red eyes worsen over time.
Some products have ingredients that act as mast cell stabilizers, which alleviate redness and swelling. Mast cell stabilizers are similar to antihistamines. But while antihistamines are known for their immediate relief, mast cell stabilizers are known for their long-lasting relief.
Antihistamines, decongestants and mast cell stabilizers are available in pill form, but pills don't work as quickly as eye drops or gels to bring eye relief.
Nonsteroidal anti-inflammatory drug (NSAID) eye drops may be prescribed to decrease swelling, inflammation and other symptoms associated with seasonal allergic conjunctivitis, also called hay fever.
Prescription corticosteroid eye drops also may provide similar, quick relief. However, steroids have been associated with side effects such as increased inner eye pressure (intraocular pressure) leading to glaucoma and damage to optic nerve. Steroids also have been known to cause the eye's natural lens to become cloudy, producing cataracts.
By Gina White, with updates by Marilyn Haddrill; reviewed by Vance Thompson, MD
