An allergy is an exaggerated immune response to a relatively harmless foreign substance, referred to as an allergen. In people without allergies, the immune response that occurs following exposure to an allergen is controlled, and produces few if any symptoms. These mediators are responsible for the symptoms of allergic reactions.
Allergic conjunctivitis is one of the most common disorders of the eye.
These symptoms may also be accompanied by large bumpy formations under the eyelid. Allergic conjunctivitis is often associated with other allergic symptoms such as hay fever, but sometimes only the eyes are affected. As its name suggests, it is related to specific pollens that spore during specific seasons. Symptoms generally include red, itchy, and watery eyes. People affected by hay fever and other seasonal allergies also experience symptoms involving the nose and throat.