Eye allergies can cause red, itchy, and watery eyes. Often, eye allergies are triggered by the same allergens that cause seasonal allergies. Potential triggers of eye allergies include airborne allergens, such as pollen or mold, as well as cosmetics and even certain foods. It is possible for the immune system to become sensitized to these triggers over time and to overreact when the body is exposed to them. Allergic reactions occur when the body is exposed to these triggers resulting in the release of histamine and other chemicals which cause the eyes to become red and to itch.