Leonhard Euler

Leonhard Euler's father was Paul Euler.Euler completed his studies at the University of Basel in 1726.Euler served as a medical lieutenant in the Russian navy from 1727 to 1730.Katharina, like Euler, was from a Swiss family.Euler's health problems began in 1735 when he had a severe fever and almost lost his life.Calinger suggests that Euler's left eye became blind from a later cataract rather than eyestrain.Even while in Berlin Euler continued to receive part of his salary from Russia.During the twenty-five years spent in Berlin, Euler wrote around 380 articles.In 1766 Euler returned to St Petersburg and Frederick was greatly angered at his departure.Soon after his return to Russia, Euler became almost entirely blind after an illness.