Ludwik Lejzer Zamenhof (1859–1917) was an eye doctor, but a rather unsuccessful one. Perhaps this was because he was more interested in a tolerant world, free from war to which he passionately wanted to make a significant contribution. Zamenhof did not make his mark as an ophthalmologist, rather he gained fame as the inventor of the world’s most famous artificial language “Esperanto.” “Ludwik Lejzer Zamenhoff, an ophthalmologist, was the inventor of Esperanto” translated into Esperanto: “Ludwik Lejzer Zamenhoff, okulkuracisto, estis la inventinto de Esperanto.”