Modern-day local anesthesia began in 1884 with a discovery by a young unknown ophthalmologist from Vienna named Carl Koller, who placed a cocaine solution on the cornea, thus producing insensibility. The news of his discovery spread throughout the world in less than a month. "Not surprisingly," a controversial priority discussion emerged. There is little information about this "dark side" of Koller's discovery and only sparse data about the personalities involved in this controversy. In addition, Carl Koller's decision to leave Vienna is also surrounded in secrecy. The story surrounding the revelation of the local anesthetic effect of cocaine and the personalities involved is fascinating and relatively unknown.