Leonhard Euler (1707–1783)

A prolific mathematician, who developed much of the notation we use, particularly in analysis (calculus). For example, naming the number pi, well, pi, was his idea. Introduced the concept of a mathematical function. Pierre-Simon Laplace said "Read Euler, Read Euler, he is the master of us all".

His eyesight worsened over time. In 1738, he got blind in his right eye, so that King Frederick called him "Cyclops". In 1766, he got blind in his left eye. He said, "Now I will have fewer distractions". He had a freak memory and ability for mental calculation, and with the aid of his scribes, Euler's productivity actually increased, producing one paper every week in the year 1775.