--- title: Ophthalmologist Ferdinand Monoyer Honored With Google Doodle description: Google's latest Doodle marks the 181st birthday of France's most famous ophthalmologist, Ferdinand Monoyer. canonical: https://time.com/4771741/ferdinand-monoyer-google-doodle-opthalmology/ author: Ryan Kilpatrick article:opinion: false article:content_tier: free article:published_time: 2017-05-09T03:00:19.000Z article:modified_time: 2026-04-13T07:43:26.607Z og:title: Google Doodle Honors Ophthalmologist Ferdinand Monoyer og:description: Monoyer developed the dioptre unit of measurement and a signature eye chart. og:url: https://time.com/4771741/ferdinand-monoyer-google-doodle-opthalmology/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt7ea8e0fb4187830b/6988cc8297cdff11aa6b09cc/ferdinand-monoyers-181st-birthday-5105939098107904-4-2xa.gif?branch=production&width=1440&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: ferdinand-monoyers-181st-birthday-5105939098107904.4-2xa og:type: article twitter:card: summary_large_image twitter:title: Google Doodle Honors Ophthalmologist Ferdinand Monoyer twitter:description: Monoyer developed the dioptre unit of measurement and a signature eye chart. twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt7ea8e0fb4187830b/6988cc8297cdff11aa6b09cc/ferdinand-monoyers-181st-birthday-5105939098107904-4-2xa.gif?branch=production&width=1440&quality=75&auto=webp&crop=16:9 ---  # Google Doodle Honors French Ophthalmologist Ferdinand Monoyer by [Ryan Kilpatrick](https://time.com/author/ryan-kilpatrick/) ## Ryan Kilpatrick May 9, 2017 3:00 AM UTC  Google by [Ryan Kilpatrick](https://time.com/author/ryan-kilpatrick/) ## Ryan Kilpatrick May 9, 2017 3:00 AM UTC Google’s latest [Doodle](https://www.google.com/doodles/ferdinand-monoyers-181st-birthday) marks the 181st birthday of France’s most famous ophthalmologist, Ferdinand Monoyer. Monoyer is best remembered for introducing the diopter, a unit of measurement for vision still used today, as well as the eponymous Monoyer chart used to test subjects’ clarity of vision. Each row in his eye chart represents a different diopter, from smallest to largest. The diopter measures the distance a person would have to be from the text to read it. Although his name might sound unfamiliar, there’s a good chance you’ve read it before if you’ve taken an eye exam: Monoyer hid his own name within his chart, reading vertically from bottom to top along each side. Born in Lyon, France in 1836, Monoyer studied medicine in Strasbourg and joined the faculty at the University of Nancy before eventually taking an academic position back in his hometown. He died there in 1912, aged 76. The Monoyer Google Doodle will appear for the search engine’s users in France and also a host of other countries in Europe, South America and Asia, as well as Canada, Australia and New Zealand. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/4771741/ferdinand-monoyer-google-doodle-opthalmology/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4771741/ferdinand-monoyer-google-doodle-opthalmology/"},"headline":"Google Doodle Honors French Ophthalmologist Ferdinand Monoyer","datePublished":"2017-05-09T03:00:19.000Z","dateModified":"2026-04-13T07:43:26.607Z","description":"Although his name might sound unfamiliar, you may have read it before if you've taken an eye exam","url":"https://time.com/4771741/ferdinand-monoyer-google-doodle-opthalmology/","keywords":["Newsfeed","Google Doodle","onetime"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt7ea8e0fb4187830b/6988cc8297cdff11aa6b09cc/ferdinand-monoyers-181st-birthday-5105939098107904-4-2xa.gif?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Ryan Kilpatrick","jobTitle":null,"url":"https://time.com/author/ryan-kilpatrick/"}],"articleSection":"","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt7ea8e0fb4187830b/6988cc8297cdff11aa6b09cc/ferdinand-monoyers-181st-birthday-5105939098107904-4-2xa.gif?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"ferdinand-monoyers-181st-birthday-5105939098107904.4-2xa","caption":"Ferdinand Monoyer Doodle","creditText":"Google","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/tag/time-section-newsfeed/","name":"Newsfeed"}},{"@type":"ListItem","position":2,"item":{"@id":"https://time.com/4771741/ferdinand-monoyer-google-doodle-opthalmology/","name":"Google Doodle Honors French Ophthalmologist Ferdinand Monoyer"}}]}] ```