Outcome measures involve comparing the right eye and left eye for severity of 12 different symptoms, that are recorded in severity on a 1-5 scale. A score of 1 means no symptoms and 5 means severe. The 12 measurements include sharp pain, dull ache, pain during movement, stinging sensation, itching, light sensitivity, watery eyes, dry eyes, sandy sensation, pressure sensation, decreased vision, and blurry vision.