Eye allergies are quite common. They occur when the eyes react to something that irritates them. Common irritants include pollen, dust, pet dander, mold and smoke. Your eyelids and conjunctiva become red, swollen and itchy. The eyes can tear and burn. Eye allergies are usually easy to diagnose. The key to treating eye allergies is to avoid or limit contact with the things causing your irritation. Over-the-counter and prescription medicines can also help control your eye allergies.