Louis Émile Javal
Encyclopedia
Louis Émile Javal was a French ophthalmologist born in Paris
. Originally trained as a civil engineer
, he switched to the medical profession, receiving his degree from the University of Paris
in 1868. Following graduation he travelled to Berlin
and studied under Albrecht von Graefe (1828-1870). During the Franco-Prussian War
he served as a medical officer. In 1878 he opened an ophthalmological laboratory at the Sorbonne
and was its director until 1900.
Javal is remembered for his studies of physiological
optics
and his work involving a disorder known as strabismus
. With his student Hjalmar August Schiøtz
(1850-1927) he constructed an early keratometer
, also known as the Javal Schiötz Ophthalmometer
. This device is used to measure the curvature of the cornea
l surface of the eye, as well as to determine the extent and axis of astigmatism
. Javal also made important contributions in regards to the study of eye tracking
, and with his assistant Marius Hans Erik Tscherning
(1854-1939), he performed studies of optics
and astigmatism.
Javal was the first to describe eye movements during reading in the late 19th century. He reported that eyes do not move continuously along a line of text, but make short rapid movements (saccades) intermingled with short stops (fixations
). Javal's observations were characterised by a reliance on naked-eye observation of eye movement in the absence of technology.
Javal's interest in strabismus
was due to the disorder affecting his father and sister. Javal himself had heterochromia
. At middle-age Javal developed glaucoma
and by 1900 was totally blind. He was a friend of Ludwik Łazarz Zamenhof (1859-1917), the inventor of Esperanto
, and stressed the importance of learning this language by the blind. In addition, he was involved in social reform issues such as education and circumstances surrounding the poor. Today the "Louis Emile Javal Silver Service Distinction" is issued by the International Contact Lens Council of Ophthalmology.
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
. Originally trained as a civil engineer
Civil engineer
A civil engineer is a person who practices civil engineering; the application of planning, designing, constructing, maintaining, and operating infrastructures while protecting the public and environmental health, as well as improving existing infrastructures that have been neglected.Originally, a...
, he switched to the medical profession, receiving his degree from the University of Paris
University of Paris
The University of Paris was a university located in Paris, France and one of the earliest to be established in Europe. It was founded in the mid 12th century, and officially recognized as a university probably between 1160 and 1250...
in 1868. Following graduation he travelled to Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...
and studied under Albrecht von Graefe (1828-1870). During the Franco-Prussian War
Franco-Prussian War
The Franco-Prussian War or Franco-German War, often referred to in France as the 1870 War was a conflict between the Second French Empire and the Kingdom of Prussia. Prussia was aided by the North German Confederation, of which it was a member, and the South German states of Baden, Württemberg and...
he served as a medical officer. In 1878 he opened an ophthalmological laboratory at the Sorbonne
Sorbonne
The Sorbonne is an edifice of the Latin Quarter, in Paris, France, which has been the historical house of the former University of Paris...
and was its director until 1900.
Javal is remembered for his studies of physiological
Physiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...
optics
Optics
Optics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...
and his work involving a disorder known as strabismus
Strabismus
Strabismus is a condition in which the eyes are not properly aligned with each other. It typically involves a lack of coordination between the extraocular muscles, which prevents bringing the gaze of each eye to the same point in space and preventing proper binocular vision, which may adversely...
. With his student Hjalmar August Schiøtz
Hjalmar August Schiøtz
Hjalmar August Schiøtz was a Norwegian ophthalmologist born in Stavanger. He studied medicine in Kristiania, Vienna and Paris. In 1884 he became head of a polyclinic for ear, nose, throat and eye diseases in Kristiania...
(1850-1927) he constructed an early keratometer
Keratometer
A keratometer, also known as a ophthalmometer, is a diagnostic instrument for measuring the curvature of the anterior surface of the cornea, particularly for assessing the extent and axis of astigmatism...
, also known as the Javal Schiötz Ophthalmometer
Keratometer
A keratometer, also known as a ophthalmometer, is a diagnostic instrument for measuring the curvature of the anterior surface of the cornea, particularly for assessing the extent and axis of astigmatism...
. This device is used to measure the curvature of the cornea
Cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...
l surface of the eye, as well as to determine the extent and axis of astigmatism
Astigmatism
An optical system with astigmatism is one where rays that propagate in two perpendicular planes have different foci. If an optical system with astigmatism is used to form an image of a cross, the vertical and horizontal lines will be in sharp focus at two different distances...
. Javal also made important contributions in regards to the study of eye tracking
Eye tracking
Eye tracking is the process of measuring either the point of gaze or the motion of an eye relative to the head. An eye tracker is a device for measuring eye positions and eye movement. Eye trackers are used in research on the visual system, in psychology, in cognitive linguistics and in product...
, and with his assistant Marius Hans Erik Tscherning
Marius Tscherning
Marius Hans Erik Tscherning was a Danish ophthalmologist.He studied ophthalmology under Edmund Hansen Grut in Copenhagen, later becoming an adjunct director at the ophthalmological laboratory at the Sorbonne in Paris. Tscherning spent 25 years at the Sorbonne, where he worked closely with Louis...
(1854-1939), he performed studies of optics
Optics
Optics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...
and astigmatism.
Javal was the first to describe eye movements during reading in the late 19th century. He reported that eyes do not move continuously along a line of text, but make short rapid movements (saccades) intermingled with short stops (fixations
Fixation (visual)
Fixation or visual fixation is the maintaining of the visual gaze on a single location. Humans typically alternate saccades and visual fixations, the notable exception being in smooth pursuit, controlled by a different neural substrate that appear to have developed for hunting prey...
). Javal's observations were characterised by a reliance on naked-eye observation of eye movement in the absence of technology.
Javal's interest in strabismus
Strabismus
Strabismus is a condition in which the eyes are not properly aligned with each other. It typically involves a lack of coordination between the extraocular muscles, which prevents bringing the gaze of each eye to the same point in space and preventing proper binocular vision, which may adversely...
was due to the disorder affecting his father and sister. Javal himself had heterochromia
Heterochromia
In anatomy, heterochromia refers to a difference in coloration, usually of the iris but also of hair or skin. Heterochromia is a result of the relative excess or lack of melanin...
. At middle-age Javal developed glaucoma
Glaucoma
Glaucoma is an eye disorder in which the optic nerve suffers damage, permanently damaging vision in the affected eye and progressing to complete blindness if untreated. It is often, but not always, associated with increased pressure of the fluid in the eye...
and by 1900 was totally blind. He was a friend of Ludwik Łazarz Zamenhof (1859-1917), the inventor of Esperanto
Esperanto
is the most widely spoken constructed international auxiliary language. Its name derives from Doktoro Esperanto , the pseudonym under which L. L. Zamenhof published the first book detailing Esperanto, the Unua Libro, in 1887...
, and stressed the importance of learning this language by the blind. In addition, he was involved in social reform issues such as education and circumstances surrounding the poor. Today the "Louis Emile Javal Silver Service Distinction" is issued by the International Contact Lens Council of Ophthalmology.