Antiaging Central NAC Eye Dops use one or two drops twice a days, or as directed by a medical health professional. Before using, read the enclosed insert carefully. ,As a soothing eye drop, for temporary relief of minor irritations to the eye and exposure to sun and wind, etc., Remove the lower ring. Turn the cap anti-clockwise to break the seal., Remove the cap, dispense drops with gentle pressure. Replace the cap after every use. Always avoid contamination by replacing cap after use.