An eye blister is a benign growth which can appear on the whites of the eyes or on the cornea itself. There are two main types of eye blister: pinguecula and pterygium.
Before x ray machines were invented, broken bones, tumors and the location of bullets were all diagnosed by physical examination and a doctor's best guess. Patients paid the price of these approaches. Then on November 8th of 1895, a German physics professor Wilhelm Conrad Roentgen made a remarkable discovery.
Shortly after the discovery of X-rays, another form of penetrating rays was discovered. In 1896, French scientist Henri Becquerel discovered natural radioactivity. Many scientists of the period were working with cathode rays, and other scientists were gathering evidence on the theory that the atom could be subdivided.