Well, yes, it is possible to make your eyes blindness when you get hit in your eyes. But that should be the eye injury led by hit. And generally speaking, one basic cause of blindness can be accidents that injure the eye. So it is possible to have blindness because if hit in your eyes. So for your situation, if it is just a small hit, you do not need to worry about it. And if you feel hurt in your eyes, you'd better go and see the eye doctor, and then just have eye exam. By the way, in daily life, just be careful about it.
It is really bad to gei hit in the eyes. I think it is quite possible to get black eyes instead of blindness. After all it is not very common to get blindness just from a hit in eyes, but it is possible. Anything is impossible, right? Eyes are very delicate organs so that they are easily to get hurt. A hit in the eye might break the capillaries in and around eyes. The blood congeled beneath skin will discolorate the area, so black eye is resulted. It causes bloodshots or even sub-conjunctivia hemorrhage at the same time. You might saw stars or totally black when you got a hit in eyes. After a few seconds, the vision will gradually come back. But if you see floaters, curtains or any other vision problems persisting or worsening, then I think it is the best choice for you to visit your ophthalmologist at the earliest. After all vision system is very complicated, it is hard to tell whether the hit damaged any fragile part.
Yes, it is really bad for you to get the hit in the eyes which may cause the deadness of the eye nerves which may cause the blindness. You should protect the eyes carefully. The strong hit on the head may also cause the damage on the eyes. If you get the hit in the eyes, you need to go to see the doctor as quickly as possible.