Inflammation of conjunctiva (Transparent membrane covering white part of the eye) is called Conjunctivitis. It is a condition where the eye turns red. Allergic conjunctivitis is caused due to allergy. The agents which cause allergies are known as allergens. Every individual is allergic to one or other substance in the environment. The most common allergens are dried grass, pollen grains etc. List of allergens are endless and individual specific. When an individual who is prone for allergy; get exposed to allergens, it causes release of some chemicals in tissue e.g. Histamines by allergy mediating cells like Mast cells. It causes itching, redness, and watering from eyes. Allergic conjunctivitis is not contagious unlike the traditional red eye or infective conjunctivitis.