Some users may experience a brief tingling sensation.Do not use if you are sensitive to any ingredient in this product. Ask a doctor before use if you have: heart disease, high blood pressure, narrow angle glaucoma, or trouble urinating due to an enlarged prostate gland. When using this product, pupils may become enlarged temporarily. Do not touch tip of container to any surface to avoid contamination. Replace cap after each use. Remove contact lenses before using. Do not use if this solution changes color or becomes cloudy. Overuse may cause more eye redness. Stop use and ask a doctor if you feel: eye pain, changes in vision occur, redness or irritation of the eye lasts, or condition worsens or lasts more than 72 hours. Keep out of reach of children. If you are pregnant or breast-feeding, ask a health professional before use. If swallowed, get medical help or contact a Poison Control Center immediately. Accidental swallowing by infants and children may lead to coma and marked reduction in body temperature.