Well, generally speaking, it is dangerous to wash your hair. As we know that it can improve your vision permanently, while there are also many things you should pay attention to it. Well, you can wash your hair, unless you can make sure your eyes can not be moistened by the water. As we know that after the surgery, your eyes will be very sensitive and fragile. So if you let the water in your eyes, your eyes will be infected easily by the viruses. So just be careful about it. Also, you should pay attention to other things. For example, you should avoid eye injuries by wearing a protective shield at night and with naps until you are advised by your doctor. Also, you should remember not sleep on the side of the operated eye for the first night.