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

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

stationed in

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

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

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

First years

Edmund Landolt was born in Kirchberg,

Switzerland Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...

, of a French mother, Rosina Baumgartner, and Swiss father, Rudolf Landolt. He came to

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

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

Study and work

Studied at

University of Zurich The University of Zurich (UZH, ) is a public university, public research university in Zurich, Switzerland. It is the largest university in Switzerland, with its 28,000 enrolled students. It was founded in 1833 from the existing colleges of the ...

where he got a Ph.D. in 1869 and was through this time and later pupil of Knapp in

Heidelberg Heidelberg (; ; ) is the List of cities in Baden-Württemberg by population, fifth-largest city in the States of Germany, German state of Baden-Württemberg, and with a population of about 163,000, of which roughly a quarter consists of studen ...

, Ferdinand Arlt in

Vienna Vienna ( ; ; ) is the capital city, capital, List of largest cities in Austria, most populous city, and one of Federal states of Austria, nine federal states of Austria. It is Austria's primate city, with just over two million inhabitants. ...

, Von Graefe and

Helmholtz Hermann Ludwig Ferdinand von Helmholtz (; ; 31 August 1821 – 8 September 1894; "von" since 1883) was a German physicist and physician who made significant contributions in several scientific fields, particularly hydrodynamic stability. The ...

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

, Horner in

Zürich Zurich (; ) is the list of cities in Switzerland, largest city in Switzerland and the capital of the canton of Zurich. It is in north-central Switzerland, at the northwestern tip of Lake Zurich. , the municipality had 448,664 inhabitants. The ...

, and Snellen and Donders in

Utrecht Utrecht ( ; ; ) is the List of cities in the Netherlands by province, fourth-largest city of the Netherlands, as well as the capital and the most populous city of the Provinces of the Netherlands, province of Utrecht (province), Utrecht. The ...

. Worked in physiological optics with, among others, Snellen and Donders. After study and practice in Utrecht and

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

he established himself in

in 1874 where he became oculist to the Institut National des Jeunes Aveugles. 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 (Pittsburgh), North Side), but lived much of her adult life in France, whe ...

, and gave her a diagnosis of

cataract A cataract is a cloudy area in the lens (anatomy), lens of the eye that leads to a visual impairment, decrease in vision of the eye. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colours, blurry or ...

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 of the outer nuclear layer of the

retina The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional ...

, investigated the functions of the ocular muscles and devised a new advancement operation. Famous for his publication of Landolt C.

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.">J. B. Lippincott Company., 1886. ** ''Refraction and accommodation of the eye and their anomalies'', Edinburgh, Young J. Pentland, 1886. * ''Cataract-operation, in our time'', [Chicago] : Ophthalmic Record, 1892. * ''Vade mecum of ophthalmological therapeutics'', Philadelphia, J. B. Lippincott Company, 1898. ** and Gygax * ''On ophthalmic surgery, being the Bowman lecture delivered on Wednesday, June 7, 1911.'', Lond. 1911. * ''Defective ocular movements and their diagnosis'', London, Frowde, 1913. ** and Marc Landolt

French

* ''Le grossissement des images ophthalmoscopiques'', Paris : Adrien Delahaye, 1874. OCLC: 16077174 * ''Sur les causes de l'amétropie'', Paris, 1877. OCLC: 79211659 * ''Leçons sur le diagnostic des maladies des yeux : faite à l'Ecole pratique de la Faculté de médicine de Paris, pendant le semester d'été 1875'', Paris : Aux Bureaux du Progrès Médical : Ve A. Delahaye, 1877. OCLC: 16867948 * ''L'œil artificiel'', Paris : Octave Doin, 1878. OCLC: 65009615 * ''Manuel d'ophthalmoscopie.'', Paris, Doin, 1878. OCLC: 14863824 * ''Clinique des maladies des yeux. Compte rendu pour l'anneé 1878'', Coulommiers : P. Brodard, 1879. OCLC: 53178656 * ''Traité complet d'ophthalmologie'', Paris : V. Adrien Delahaye, 1880-1889. OCLC: 9766547 ** and Louis de Wecker. ** Ed. 2.: Paris, Lecrosnier et Babé, 1880-89. OCLC: 14860559 * ''Tableau synoptique des mouvements des yeux & de leurs anomalies'', Paris : Martinet, a.1880OCLC: 67734772 * ''Tableau synoptique des mouvements des yeux et de leurs anomalies'', .l. : s.n., 188-? OCLC: 61653001 ** aa. Librairie médicale scientifique vigot frères, * ''Notice biographique à la mémoire du Docteur C ohannF iedrichHorner, professeur d'ophthalmologie à l'Université de Zurich'', Paris : .n. 1887. OCLC: 81850385 ** and C Johann Friedrich Horner * ''Notice biographique à la mémoire du Docteur T.F. Horner, professeur d'ophthalmologie à l'Université de Zurich'', Paris, 1887. OCLC: 82939545 * ''Rapport sur la question du strabisme, preś. au VIIe Congreś international d'ophthalmologie à Heidelberg'', Wiesbaden, 1888. OCLC: 67724682 * ''Opto-types simples. 2 circular disks'', Paris : O. Doin, 1889. OCLC: 53178663 * ''F. C. Donders'', Paris : Steinheil, 1889. OCLC: 69060626 * ''Un nouveau procédé d'opération dans le distichiasis'', Paris, 1890. OCLC: 67724675 * ''Un nouveau cas d'achromatopsie totale'', Paris : G. Steinheil, 1891. OCLC: 53178653 * ''H. de Helmholtz : esquisse biographique'', .l. : s.n. 1894. OCLC: 65101525 ** and H. de Helmholtz * ''Précis de thérapeutique ophtalmologique'', Paris, Masson, 1895. OCLC: 14808861 ** and Gygax * ''Nouveaux objets-types pour la de\´ermination de lacute visuelle'', Paris : Doin, 1899. OCLC: 65087355 * ''Nouveau objets-types pour la détermination de l'acuité visuelle.'', Paris : O. Doin, 1899. OCLC: 53178619 * ''Souvenirs sur H.Snellen'', Paris : Steinheil, 1908. OCLC: 67520817 * ''Diagnostic des troubles de la motilité oculaire'', Paris, Masson, 1909. Ed. française par Marc Landolt OCLC: 14785955 * ''Examen des mouvements normaux & pathologiques des yeux'', Paris, G. Steinheil, 1916. OCLC: 5856097

Family

Married Valerie Hübscher. Two sons; Dr. Fernand Landolt, laryngologist and Dr. Marc Landolt,

Curiosity

He is mentioned in

Sherlock Holmes Sherlock Holmes () is a Detective fiction, fictional detective created by British author Arthur Conan Doyle. Referring to himself as a "Private investigator, consulting detective" in his stories, Holmes is known for his proficiency with obser ...

' book ''The Demon Device'' (Robert Saffron) p. 44. Sir Arthur Conan Doyle spent time with him in

in relation to his study in

. Sir Arthur Conan Doyle: the author was ophthalmologist
by MD James G. Ravin in '' Survey of Ophthalmology'', November, 1995.