There is a clear, thin membrane called the conjunctiva which covers the eyeball and the inner part of the eyelids. Allergy is caused when something irritates this covering. It makes the eye red and swollen. They also might start itching, hurting or getting watery. This is called conjunctivitis also known as "pink eye."

Exact causes cannot be pin pointed but there are irritants in the air that can cause allergies. Inheritance is also a major cause. Allergens that can cause allergies include Smoke and air pollution, skin medicines or other cosmetics, animal secretions an hair, pollen from trees, ragweed and grass and perfumes

Aviod allergens.