Well, when blood and other fluids collect in the space around the eye, a black eye can occur. And according to some researches, it is often caused by the injury to the eyes, face or the head. And air bag can also lead to injury to your eyes, leading to black eyes. In the case of a car air bag inflating, eye injuries can occur. The force of impact can cause a blow to the eye, foreign objects may enter the eye, and chemicals in the air bag can burn the eye. And then, you will get black eyes. To treat a black eye, you can try using ice to reduce the swelling caused by a black eye. In this way, the bruising will start fading in a few days. And then, go and see the eye doctor as soon as possible.