Refracting telescope
Refractors were the earliest type of optical telescope. The first practical refracting telescopes appeared in the Netherlands about 1608, and were credited to three individuals, Hans Lippershey and Zacharias Janssen, spectacle-makers in Middelburg, and Jacob Metius of Alkmaar. Galileo Galilei, happening to be in Venice in about the month of May 1609, heard of the invention and constructed a version of his own. Galileo then communicated the details of his invention to the public, and presented the instrument itself to the Doge Leonardo Donato, sitting in full council.
Juan Roget
A 1959 research paper by Simón de Guilleuma claimed that evidence he had uncovered pointed to the French born spectacle maker, Juan Roget, as the inventor of the telescope before Hans Lipperhey's patent application for the same device in October 1608 and that Dutch spectacle makers had copied Roget's device. Guilleuma referenced a book published in 1618, ""Telescopium: sive ars perficiendi novum illud Galilaei visorium instrumentum ad sydera in tres partes divisa"" ("Telescope, or a performance of the art and means to Galileos's new vision of the stars, in three volumes") by Italian author Hieronymi Sirturi Mediolanensis (aka Girolamo Sirtori of Milan) in which the author describes a 1609 meeting with a "withered old" spectacle maker in Girona named "Roget" who claimed to have invented the telescope. Simón de Guilleuma researched the register of deaths of Rodez Cathedral in Aveyron and found that there was a "Roget" family of spectacle makers, leading him to conclude that the spectacle maker in the Sirtori story was Juan Roget.