I used this kind of products. It could help whiten the white part in your eyes. As we aging, the white part of eyes are getting yellow or red. The yellow or red eyes make people look old, listless and tired. So people use this eye whitening drops to clear the blood spots in eyes. If you instill the drops again and again, finally, you will find that you need to instill the drops more and more frequently. Once you stoped, you will find your eyes are much redder. According to the doctor, this kind of whitening drops like Visine and Murine, can only be used 3-4times each week. If overdose it, after the vasoconstricting effect goes off, the drops would cause the rebound redness. To avoid red or yellow eyes, we'd better protect our eyes from wind, sun rays, dust, or any other possible damages. Don't rub your eyes. Wash your hands thoroughly with mild soap every time you need to touch your eyes or contact lenses. Whenever you need to face strong light, like glare or sun rays, make sure to wear the sunglasses to protect your eyes.