The following year, the intense beam of light was put to its first medical use by Dr. Charles J. Campbell of the Edward S. Harkness Eye Institute, at what was then known as Columbia-Presbyterian Medical Center (now NewYork-Presbyterian/Columbia University Medical Center). On November 22, 1961, while working alongside Dr. Charles Koester, a representative of American Optical Co., which had supplied the laser, Campbell utilized the device to treat a patient’s retinal tumor. The tumor, an angioma, was destroyed with a single pulse that lasted about one thousandth of a second. Besides being incredibly fast, the laser was far more comfortable for the patient than the 1,000-watt xenon arc lamps that were being used in similar operations. In the years to come, the ruby laser was used in various medical treatments. In addition to its continued application in ophthalmology, including LASIK, it’s also commonly employed to treat cancer and conduct surgeries in the fields of gynecology, dermatology, and gastroenterology.