Used primarily as an antihistamine in ophthalmic formulations to treat allergic conjunctivitis. It helps relieve symptoms such as itching, redness, and swelling of the eyes caused by seasonal allergies. Its dual action includes blocking H1 histamine receptors and stabilizing mast cells, preventing the release of allergic mediators. Due to its rapid onset and prolonged effect, it is commonly found in prescription eye drops for both acute and chronic ocular allergy management.