Well, all medicines can have some kinds of side effects. But some side effects are minor while some are serious. As to visine red eye drops, it may cause tearing, blurring, stinging of the eye, or dilation of pupils. if you have any kind of these symptoms, you just need to stop using this eye drops and the symptom will go away on its own. But if you are suffering from severe side effects such as hives, rash, difficulty breathing, swelling of the mouth, face, lips, or tongue, tightness in the chest, continued redness or irritation of the eye, eye pain, change in vision, or even headaches, you may need to seek for medical treatment right away.