Other Eye Conditions
Eye allergies are often hereditary, and occur due to mechanisms similar to systemic allergies. Your body may be overreacting to a substance perceived as harmful, even though it may not be. For example, dust or cat dander does not bother many people, but other people react with congestion, a runny nose, and swollen eyes. Their bodies react to these substances with increased release of a chemical called histamine. Many of these substances, or allergens, are in the air, where they come in contact with your eyes and nose. Common allergens include pollen, mold, dust, and pet dander. Some cosmetics or antibiotic eye drops can also cause eye allergies. Some people are even allergic to the preservatives in eye drops, such as artificial tears that are used to lubricate dry eyes.
The most common treatment is to avoid what is causing your eye allergy. Try to keep your home free of pet dander and dust. Stay inside with the air conditioner on when the pollen count is high. The air conditioner can filter out allergens if you clean them periodically.Medications
If you are not sure what is causing your eye allergies, or you are not having any luck even with avoidance, the next step is usually medications.
Over-the-counter and prescription medications are available, and both have their advantages. Usually OTC medications are less expensive, but prescription medicines are usually stronger.
The pills or eye drops have one of several different active ingredients: antihistamines, decongestants, and mast cell stabilizers are the most common. Antihistamines can help relieve many systemic symptoms caused by airborne allergens, such as itchy eyes, runny nose, and sneezing. However, they can aggravate dry eye symptoms. Decongestants can help shrink swollen nasal passages to allow for easier breathing, as well as decrease redness due to vasoconstriction of blood vessels. Mast cell stabilizers can help alleviate redness and swelling.
Other anti-inflammatory eye drops such as steroids and NSAIDs may be given in severe allergic cases for acute relief.