I was so excited to try this serum...unfortunately my enthusiasm was short-lived. I only used the product for four days. By the afternoon after the fourth use I had to go home from running errands to take my contacts out. My eyes were red, itchy, and, kept tearing up. I had to wear my glasses the rest of the day. So disappointed. I will never use this product again. I regret ever purchasing it. User's recommendation: Do not buy...