Murine Irritation & Redness Relief Eye Drops are specially formulated to clear and soothe red and irritated eyes. Eyes can become irritated by many different factors including dusty atmospheres, wind, swimming, smoke, air pollutants and close work such as reading and using computers. Murine contains the active ingredient naphazoline hydrochloride, which belongs to a group of medicines called local vasoconstrictors. The ingredient acts by narrowing the blood vessels in the eyes in order to reduce redness and swelling. It includes a fast-acting and long-lasting action.