When doing eye checks – whether minus, plus, or cylindrical – are often asked to read a chart containing a row of letters. The letters vary in size. Initially, someone will be asked to read the largest letters, then move to a smaller letter that is more difficult to read. From there then an ophthalmologist or eye lens practitioner can determine the condition of one’s eyes, including determining the size of the lens for eyeglasses.
Do you know who the inventor of this model of eye examination? He is Ferdinand Monoyer. His profession as an eye doctor born in 1836 in France. His father was a French military doctor who had abandoned him from the age of five. His mother then married to an eye doctor named Victor Stoeber who teaches at the University of Strasbourg.
Monoyer studied eye science also at the university with his two half sisters. And, his greatest achievements throughout his teaching career in medical school and traveling to various universities in Europe are dioptre. Eye examination by dioptre method is still used today.
“Dioptre is used to measure the distance from eye to text. Monoyer composes an eye chart with each line representing a dioptre that is different from the smallest to the largest,” wrote Google that made Google Doodle some time ago, as quoted by the BBC page.
The word “Monoyer” comes inserted in a row of letters. This can be read in the chart on the second list from the bottom, left side. The word “Monoyer” can be found by reading from bottom to top.
The dioptre chart is progressing. In the year 1862, an ophthalmologist named Herman Snellen from the Netherlands made it with an abstract symbol and subsequently replaced the letters. It’s just the most recent chart developed by Astralia researchers in 1976, named LogMAR. However, the base of manufacture still refers to the chart developed by Monoyer and Snellen.