Ferdinand Monoyer: 5 Fast Facts You Need to Know

Ferdinand Monoryer's 181st Birthday, today's google doodle, Ferdinand Monoyer


The May 9 Google Doodle celebrates the life of Ferdinand Monoyer, the famed French ophthalmologist who created the diopter, a unit of measurement for vision still used today. He also invented the Moyoner chart.

May 9, 2017 would mark Monoyer’s 181st birthday. Although his best-known achievements were made over 140 years ago, his work is still important today, especially for those who need glasses.

As Google notes:

Monoyer was known to change the font of a particular letter if it didn’t suit him; after all, if you’re going to judge a person’s vision by it, that letter had better be as legible as possible! If you look closely at today’s Doodle, you might be able to spot a tribute to another of Monoyer’s signatures: his name, hidden in the chart.

Here’s what you need to know about Monoyer.

1. Monoyer Invented the Diopter, the Unit of Measurement for Vision

ferdinand monoyer

Ferdinand Monoyer. (Wikimedia Commons)

In 1872, Moyoner made his biggest contrition to ophthalmology, which is the branch of medicine concerning the eyeball. He developed the diopter (or dioptre in the U.K.). Diopter is the unit of measurement for the optical power of a lens.

Magnifiers: What is a Diopter?A diopter is a unit of measurement for lens power. Here is a list of benchtop magnifiers with diopters: hmcelectronics.com/Inspection-Instruments/Magnifiers-Benchtop2013-09-05T12:44:44.000Z

The above video explains what a diopter is. Here’s the dictionary definition:

a unit of measure of the refractive power of a lens, having the dimension of the reciprocal of length and a unit equal to the reciprocal of one meter

2. Monoyer Hid His Name in the Monoyer Vision Test

Almanac: The eye chartJanuary 18, 1908, is the anniversary of the death of Dutch ophthalmologist Herman Snellen, who created the familiar test for visual acuity. Charles Osgood reports.2015-01-18T15:00:30.000Z

Monoyer was also the developer of the Monoyer chart. This is used to test visual acuity, or how well the retina focuses.

Monoyer actually hid his own name in the test he used, much like an “easter egg.” The first letter of each line, from the second row through the sixth, spells out his last name. The last letter from each line, beginning at the second through the 10th line, spells out his first name.

However, the Snellen chart is more common. It was developed in 1862 by Herman Snellen. Monoyer’s chart is still used as well though.

3. He Was an Ophthalmologist, Which Is Different from an Optometrist or Optician

A Career in Ophthalmology with The Eye Institute (JTJS92014)In this story we discover how to become an Ophthalmologist and discover how advances in technology is revolutionising eye surgery2014-07-22T07:15:04.000Z

Monoyer was an ophthalmologist, not an optometrist or optician. These are all three very different eye care professionals.

As the American Association for Pediatric Ophthalmology and Strabismus explains, an ophthalmologist is a medical doctor who specializes in eye and vision care. Unlike an optometrist and optician, an ophthalmologist is licensed to be a surgeon and practice medicine. They also diagnose all eye disease and prescribes eyeglasses or contact lenses. Many also take part in scientific studies in their field.

An optometrist cannot perform surgery, but can test and treat vision changes. “They are licensed to practice optometry, which primarily involves performing eye exams and vision tests, prescribing and dispensing corrective lenses, detecting certain eye abnormalities, and prescribing medications for certain eye diseases,” according to the AAPOS.

Lastly, an optician is a technician who designs and fits eyeglasses and frames to correct eyesight. They cannot diagnose or treat eye diseases or write prescriptions.

4. Monoyer Died in 1912 at Age 76

VideoVideo related to ferdinand monoyer: 5 fast facts you need to know2017-05-08T14:24:15-04:00

Monoyer died on July 13, 1912. According to Lyon Medical in 1912, members of the Faculty of Medicine at the University of Lyon followed his casket to his grave in a procession to honor his work.

“To the memory of this scholar, the Medical Society bows with respect and sadness; she has lost a friend who was also her counselor who knew to think and to reflect,” the President of the Société nationale de Médecine de Lyon said in a speech in Monoyer’s honor two months after his death.

The University of Lyon was the last university Monoyer taught at, from 1877 to 1909. He was also a professor at the University of Strasbourg and at the University of Nancy from 1872 to 1877.

5. Monoyer’s Father Was a Military Doctor Who Died When Monoyer Was 5 Years Old

VideoVideo related to ferdinand monoyer: 5 fast facts you need to know2017-05-08T14:24:15-04:00

Monoyer’s villa in Lyon remains preserved for visitors and is open for events. According to the villa’s website, Monoyer’s father was a military doctor who died when Monoyer was just 5 years old. Monoyer’s mother, Jeanne, then married Professor Victor Stoeber, who had two daughters of his own, and they moved to Strasbourg.

Monoyer studied in several major European universities before returning to Strasbourg and deciding to become an ophthalmologist. When Stoeber died, Monoyer took his place at the University of Strasbourg. While there, he helped the wounded during the Franco-Prussian War.

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