ketotifen

This is a second generation antihistamine medication found in several of the better over-the-counter allergy eye drops. This medicine can be found at the store under the trade names Zaditor and Alaway. There are generic drops as well … but not much cheaper than the brand names. Allergy medications like this are good for treating itchy eyes and ocular swelling.  The half-life is about 12 hours, so this drop is commonly dosed twice a day.