With X-rays, doctors detect problems human eyes can't see. X-rays are a form of invisible radiation. This powerful medical technology helps experts look inside the body and even treat illnesses. But early on, X-rays caused harm too, as people used them without enough protection. This graphic history covers the discovery of X-rays, the development of safety standards, and the rise of more powerful and precise X-ray machines. Find out how modern doctors create digital images of the inner body—even 3D images of our brains!