Well, in my opinion, side bangs cannot lead to lazy eyes, but black eye. As we know that lazy eye means that one eye has not developed normally. And at that time, blurred vision can be possible. But side bangs cannot cause it, while black eyes will occur. According to some researches, black eye is often caused by the injury to the eyes, face or the head. And when your eyes suffer side bangs, the blood and other fluids will collect in the space around the eye. And at that time, a black eye will occur. For the treatments, you can try using ice to reduce the swelling caused by a black eye. And it will be fine.