Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Stop using this medicine and call your doctor at once if you have:
eye pain or changes in vision;
eye itching that gets worse or lasts longer than 72 hours;
severe burning, stinging, or irritation after using this medicine; or
eye swelling, redness, severe discomfort, crusting or drainage (may be signs of infection).
Less serious side effects may be more likely, and you may have none at all.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Olopatadine ophthalmic side effects (more detail)
