Biomedical subjects
Mogens Norn
Publications and source records attributed to Mogens Norn.
Marius Tscherning (1854-1939): his life and work in optical physiology.
BACKGROUND: This article is based on Tscherning's papers, scientific protocols and letters and the many original instruments kept in the Medical History Museum in Copenhagen, Denmark. HISTORY: In 1884, after his thesis concerning the frequency of myopia in Denmark, Tscherning became adjunct director of the ophthalmological laboratory at the Sorbonne University in Paris. He was called back to Denmark in 1910 and appointed professor of ophthalmology and head of the Eye Department, Rigshospitalet. He continued to work scientifically as emeritus from 1925. ACHIEVEMENTS: Tscherning published about 100 scientific papers, mainly concerning optical physiology (i.e. the aetiology of myopia, entoptic phenomena, Purkinje pictures, the polygonal pattern provoked by corneal rubbing, etc.). He studied the law of Listing and projections depending on torsion of the eye and invented the ophthalmophacometer, which measures the changes that occur in the front and back curvatures of the crystalline lens during accommodation. Tscherning also studied aberration and calculated and constructed forward bulging periscopic (punctal) spectacle lenses. In addition, he studied colour sense, dark vision and adaptation.
[Dark visions and adaptation in Danish ophthalmology 1889-1940].
The scotopticometer is a small, light and handy instrument from 1935, which was developed in Denmark by Carsten Edmund Zeuthen (1897-1973) and Hans Ulrik Møller (1894-1954) for the measurement of dark vision without the use of a dark chamber. The prerequisites are Jannik Bjerrum's contrast letters from 1889 and Marius Tscherning's photometric neutral-gray filter-glasses with a logaritmic scale (Ph 1-8); both Bjerrum (1851-1920) and Tscherning (1854-1939) were Danish ophthalmologists. Tescherning's basic experiments and theories are reported, based on a study of his scientific publications, scientific protocols, letters and scrapbook. Tscherning inspired many young Danish scientists to further studies of dark adaptation, which is still an important topic (traffic, military, art, illumination, gerontology).
[Analysis of iris: history and future].
Analysis of the iris has ancient roots, but iridology in its present sense was established by Philippi Meyers in 1670. The discipline was further developed by Ignaz Péczely in 1881 and by Nils Liljequist in 1890. Other studies have been published in Germany, Sweden, Norway, England, France, USA, Australia and elsewhere, and iridology is practiced worldwide. The techniques used are described and the sources of error are mentioned when several photos from the same patient are compared (e.g. the influences of differences in pupil size, magnification and the effect of oblique light). The iris key (irigraphy) and the interpretation of different sights are discussed in some detail; there is little agreement among iridologists. Some iris diagnoses are of little interest to day and some modern diseases are missing in the diagnostic system. Controlled studies reveal that iridology is of no use whatsoever for the detection of cancer and other diseases in the stomach, intestines, kidney, lungs and heart. The reason for the continued popularity of iridology is discussed, and it is concluded that this type of alternative medicine is not harmless.
The Society's archives.
The archives and minutes of the Ophthalmological Society have now been donated to the Medical History Museum of the University of Copenhagen. The first two minutes in the archives are hand-written and cover the period 1900-52. The third minute, mainly typewritten, goes up to 1971. The rest consists of papers, photos, albums, correspondence, gifts etc. Also mentioned are venues for the meetings from Kongens Nytorv (Royal New Square) to various hospitals in Copenhagen etc., finances, many celebrations, meetings, demonstrations, discussions relating to papers, Nordic meetings, relations with opticians, engineers (lighting), printing and certificates (driving, seamen). The archives call for further investigation.
Objects relating to the Danish Ophthalmological Society at the Medical History Museum.
Some of the objects from the Medical History Museum, University of Copenhagen, concerned with the century-old Danish Ophthalmological Society are mentioned, together with some objects concerned with our predecessors. Jannik Bjerrum's campimeter at 1-2 m-distance reveals glaucomatous arcuate scotoma. [figure: see text] Marius Tscherning's many scientific papers and his ophthalmophacometer (also measuring accommodation), abberoscope, adaptoscope, colour vision, punctual meniscen spectacle glasses etc. are housed in the Museum. K.K.K. Lundsgaard's spectacle collection and cataract paper, Gordon Norrie's colour vision lantern and his personal pince-nez are described. Gustav Østerberg's contact lens practice and his pictorial visual chart, Jørn Boberg-Ans' pioneer artificial lens surgery dating from 1958, are all examples of the work of members of the Society. From our predecessors, we refer to the first cataract extraction in Denmark in 1670 (F. Borri on a goose); Georg Heuermann's on humans dating from 1755 and the reintroduction of the operation in 1810 by C.C. Withusen, V. Krenchel's (1844-1885) ophthalmoscope with a movable mirror and his colour vision lantern; A. Stadfeldt's instruments for examination of the refractive index of the human lens, MD thesis dating from 1898. In addition, snow goggles from Greenland and eye-baths are described.
[Space perception: the history and its significance for art].
Some aspects of the opthalmologic history of Denmark are briefly mentioned. Lens extraction in 1667 in Copenhagen, Edmund Hansen Gruts stereoophtalmoscopy in 1857, Ludvig Panums area in 1858 (single vision) space perception and outside this area double vision), squint treatment, Marius Tschernings periscopic spectacle lenses, Henning Rønnes stereoortograph and keiroscope and Gerhard Rønnes stereoscope. Space perception depends mostly on binocular function (convergens), but in fact some space perception occurs in vision due to perspective, accommodation, parallaxe, blurring, colours and shadows. The Danisk Poet, Hans Christian Andersen, has in his novels mentioned latent squint. The German poet Rainer Maria Rilke was much interested in perspective in connection with the development of impressionism, especially Paul Cézanne. Rilke in his later period developed the view that concentration on perspective removed those essential aspects from the world, in which he found God or a fourth dimension, as exemplified in the presence of ghosts.