Yes, blow head can lead to retinal detachment. Generally speaking, a strong blow to the head can cause the retina to pull away from its underlying wall. In that way, once the retina has started to detached, the fluid from the Vitreous flows in the small tears in the retina can occur. And then retina will start to detach. Anyway, it can be kind of dangerous. So just be careful about it. And you should know that there are many other factors which can lead to retinal detachment, such as eye injury, severe high blood pressure. On the other hand, most people with detached retina risk factors will not develop a detached retina. So you should not worry about it too much. If you have some questions about it, just ask your doctor, he can give you the professional answer.