All About Ferdinand Monoyer

Ferdinand Monoyer was a pioneer in the field of eye sight, developing measurements and systems that we still use today

He is best known for creating the Monoyer chart, as well as introducing the dioptre as a measurement for visual clarity. Monoyer eye chart
The dioptre measures the distance you’d have to be from text to read it.

Monoyer is most famous for having devised an eye chart where every row represents a different dioptre, from smallest to largest.
Cheekily, he hid his name in the side of the chart.

Ferdinand Monoyer was born in France in 1836.  He grew up in Lyon before moving to the University of Strasbourg in 1871 and eventually returned to Lyon, were he died aged 76 in 1912.