Jacques Rodolphe Edmund Landolt (17 May 1846 – 9 May 1926) was a Swiss ophthalmologist stationed in

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), ma ...

, mostly known for a wide range of publications and his research in the field of

ophthalmology Ophthalmology ( ) is a surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a medic ...

First years

Edmund Landolt was born in Kirchberg, Switzerland, of a French mother, Rosina Baumgartner, and Swiss father, Rudolf Landolt. He came to

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

during the war in 1871 with a Swiss ambulance hospital, and was present at the battles around Belfort, where he contracted

enteric fever Typhoid fever, also known as typhoid, is a disease caused by '' Salmonella'' serotype Typhi bacteria. Symptoms vary from mild to severe, and usually begin six to 30 days after exposure. Often there is a gradual onset of a high fever over several ...

Study and work

Studied at

University of Zurich The University of Zürich (UZH, german: Universität Zürich) is a public research university located in the city of Zürich, Switzerland. It is the largest university in Switzerland, with its 28,000 enrolled students. It was founded in 1833 f ...

where he got a

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is ...

in 1869 and was through this time and later pupil of

Knapp Knapp may refer to: People * Knapp (surname) Places * Knapp, Dunn County, Wisconsin * Knapp, Jackson County, Wisconsin * Knapp, Hampshire, England, a village in the parish of Ampfield * Knapp, Perthshire, Scotland * Knapp Creek (West Virgi ...

Heidelberg Heidelberg (; Palatine German language, Palatine German: ''Heidlberg'') is a city in the States of Germany, German state of Baden-Württemberg, situated on the river Neckar in south-west Germany. As of the 2016 census, its population was 159,914 ...

, Ferdinand Arlt in

Vienna en, Viennese , iso_code = AT-9 , registration_plate = W , postal_code_type = Postal code , postal_code = , timezone = CET , utc_offset = +1 , timezone_DST ...

, Von Graefe and Helmholtz in

Berlin Berlin ( , ) is the capital and List of cities in Germany by population, largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's List of cities in the European Union by population within ci ...

Horner Horner is an English and German surname that derives from the Middle English word for the occupation ''horner'', meaning horn-worker or horn-maker, or even horn-blower. People *Alison Horner (born 1966), British businesswoman * Arthur Horner (dis ...

Zürich , neighboring_municipalities = Adliswil, Dübendorf, Fällanden, Kilchberg, Maur, Oberengstringen, Opfikon, Regensdorf, Rümlang, Schlieren, Stallikon, Uitikon, Urdorf, Wallisellen, Zollikon , twintowns = Kunming, San Francisco Zürich ...

, and

Snellen Snellen is a Dutch surname. ''Snel'' means "quick" in Dutch and the original bearer of the name may have been a lively person. However, the origin of the surname often was patronymic, as Snel and Snelle were short forms of the archaic Germanic give ...

and Donders in

Utrecht Utrecht ( , , ) is the fourth-largest city and a municipality of the Netherlands, capital and most populous city of the province of Utrecht. It is located in the eastern corner of the Randstad conurbation, in the very centre of mainland Net ...

. Worked in physiological optics with, among others,

and Donders. After study and practice in Utrecht and

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

he established himself in

in 1874 where he became

oculist Ophthalmology ( ) is a surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a medic ...

to the

Institut National des Jeunes Aveugles Institut National des Jeunes Aveugles (''National Institute for Blind Children'' or ''Royal Institution for Blind Youth''), in Paris, was the first special school for blind students in the world, and served as a model for many subsequent schools ...

. With Panas (1832–1903) and Poncet (1849–1913) he re-founded the Archives d'ophtalmologie in 1881 and co-directed the Laboratoire d’Ophtalmologie with Javal. Landolt's eye clinic on the Rue Saint-André-des-Arts was world-famous. There he treated, among others,

Mary Cassatt Mary Stevenson Cassatt (; May 22, 1844June 14, 1926) was an American painter and printmaker. She was born in Allegheny, Pennsylvania (now part of Pittsburgh's North Side), but lived much of her adult life in France, where she befriended Edgar De ...

, and gave her a diagnosis of

cataract A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble ...

Special fields of work

Ocular muscles and their disorders. Pioneering the work in their study and treatment. He discovered “Landolt's bodies” between the rods and

cones A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines conn ...

of the

outer nuclear layer The outer nuclear layer (or layer of outer granules or external nuclear layer), is one of the layers of the vertebrate retina The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates ...

of the

retina The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then ...

, investigated the functions of the

ocular muscles The extraocular muscles (extrinsic ocular muscles), are the seven extrinsic muscles of the human eye. Six of the extraocular muscles, the four recti muscles, and the superior and inferior oblique muscles, control movement of the eye and the othe ...

and devised a new advancement operation. Famous for his publication of

Landolt C The Landolt C, also known as a Landolt ring, Landolt broken ring, or Japanese vision test, is an optotype: a standardized symbol used for testing vision. It was developed by the Swiss-born ophthalmologist Edmund Landolt. The Landolt C consists ...

Publications

English

* ''The introduction of the metrical system into ophthalmology'', London : J. & A. Churchill, 1876. * ''The artificial eye'', London : Trübner & Co., 1879. ** tr. Edgar Athelstane Browne * ''A manual of examination of the eyes. A course of lectures delivered at the "Ećole pratique,"'', Philadelphia, D. G. Brinton, 1879. ** tr. Swan M Burnett * ''A manual of examination of the eyes. A course of lectures delivered at the "École pratique,"'', Philadelphia, D. G. Brinton, 1879. ** Ed. 2.: London : Baillie're, Tindall & Cox, 1879. * ''On myopia'', London : Harrison and Sons, 1879. * ''On insufficiency of the power of convergence'', .l._:_[s.n._1886._ *_''The_refraction_and_accommodation_of_the_eye_and_their_anomalies'',_Edinburgh,_Pentland,_1886._ **_Ed._2.:_Phila.,_J._B._Lippincott_&_Co..html" "title=".n..html" ;"title=".l. : [s.n.">.l. : [s.n. 1886. * ''The refraction and accommodation of the eye and their anomalies'', Edinburgh, Pentland, 1886. ** Ed. 2.: Phila., J. B. Lippincott & Co.">J. B. Lippincott Company J. B. Lippincott & Co. was an American publishing house founded in Philadelphia, Pennsylvania in 1836 by Joshua Ballinger Lippincott. It was incorporated in 1885 as J. B. Lippincott Company. History 1836–1977 Joshua Ballinger Lippincott (Marc ...

First years

Study and work

Special fields of work

Publications

English

French

Family

Curiosity

References

External links

Stub