What is Patanol eye drop used for? Patanol eye drop contains Olopatadine, which is a medicine for treating and controlling allergic conditions of the eye. It works in two different manners by reducing and controlling the intensity of the allergic reaction. Olopatadine eye drop is used for treating itchy eyes associated with seasonal allergic conjunctivitis. Allergic conjunctivitis refers to allergic reactions caused by materials (allergens) like pollens, house dust, or animal fur, resulting in itching, redness, and swelling of the surface of your eye.