Carl Friedrich Richard Förster (15 November 1825 – 7 July 1902) was a German

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 ...

born in the town of Lissa (today

Leszno Leszno (, , ) is a historic city in western Poland, seat of Leszno County within the Greater Poland Voivodeship. It is the seventh-largest city in the province with an estimated population of 62,200, as of 2021. Leszno is a former residential cit ...

, Poland). He received his medical doctorate in 1849, and for most of his career was associated with the

University of Breslau A university () is an educational institution, institution of tertiary education and research which awards academic degrees in several Discipline (academia), academic disciplines. ''University'' is derived from the Latin phrase , which roughly ...

. Two of his assistants at Breslau were Hermann Wilbrand (1851–1935) and

Hermann Rudolph Aubert Hermann Rudolph Aubert (November 23, 1826 – February 12, 1892) was a German physiologist born in Frankfurt (Oder), Frankfurt. In 1850 he obtained his medical doctorate, afterwards serving as privat-docent of physiology at Breslau (1854). In 186 ...

(1826–1892). Förster is remembered for conducting tests of

visual acuity Visual acuity (VA) commonly refers to the clarity of visual perception, vision, but technically rates an animal's ability to recognize small details with precision. Visual acuity depends on optical and neural factors. Optical factors of the eye ...

, and for his investigations of indirect vision (

peripheral vision Peripheral vision, or ''indirect vision'', is vision as it occurs outside the point of fixation, i.e. away from the center of gaze or, when viewed at large angles, in (or out of) the "corner of one's eye". The vast majority of the area in the ...

) and visual performance across the

visual field The visual field is "that portion of space in which objects are visible at the same moment during steady fixation of the gaze in one direction"; in ophthalmology and neurology the emphasis is mostly on the structure inside the visual field and it i ...

together with Hermann Aubert. The linear variation of visual performance that they described is sometimes referred to as the Aubert-Foerster law. From Förster's research, the eponymous terms of "Förster perimeter" and "Förster's shift" are derived. A Förster perimeter was an instrument used to measure an individual's field of vision. He also devised a specialized

photometer A photometer is an instrument that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum. Most photometers convert light into an electric current using a photoresistor, ...

to determine the smallest amount of light that will permit an object to be visible. In 1871 Förster defined the difference between negative and positive

scotoma A scotoma is an area of partial alteration in the field of vision consisting of a partially diminished or entirely degenerated visual acuity that is surrounded by a field of normal – or relatively well-preserved – vision. Every normal mamm ...

(blind spot); if vision of the scotoma region is a void, it is a negative scotoma, and if the scotoma is an area of darkness/lightness or composed of hallucinatory patterns, it is called a positive scotoma.

Written works

* ''Beiträge zur Kenntniss des indirecten Sehens''.

Albrecht von Graefe Albrecht von Graefe may refer to: * Albrecht von Graefe (ophthalmologist) (1828-1870), Prussian ophthalmologist * Albrecht von Graefe (politician) (1868-1933), German politician and landowner {{hndis, Graefe, Albrecht von ...

's Archiv für Ophthalmologie, Berlin, 1857, 3: 167, Aubert, R. F. Foerster. * ''Ophtalmologische Beiträge''. Berlin, 1862. * ''Beziehungen der Allgemein-Leiden und Organ-Erkrankungen zu Veränderungen und Erkrankungen des Sehorgans''. In:

Edwin Theodor Saemisch Edwin Theodor Saemisch (30 September 1833, Luckau – 29 September 1909, Bonn) was a German ophthalmologist born in Luckau. In 1858 he received his medical doctorate from the University of Berlin, afterwards serving as an assistant to Albrech ...

and Alfred Carl Graefe: Handbuch der gesammten Augenheilkunde. Leipzig 1877, 7, Theil 5, pp. 59–234. * ''Lichtsinn bei Krankheiten der Chorioidea und Retina''. Klin Mbl Augenheilk 1871; 9: 337-346. * ''Künstliche Reifung des Cataracts''. Hermann Jakob Knapp’s Archiv für Augenheilkunde, Wiesbaden, 1883. * ''Verbreitung der Cholera durch die Brunnen''.

Carl Wilhelm von Zehender Carl Wilhelm von Zehender (21 May 1819 – 19 December 1916) was a German ophthalmologist born in Bremen. He studied medicine at the universities of Göttingen, Jena and Kiel, receiving his doctorate in 1845. He studied ophthalmology in Paris as ...

’s Klinische Monatsblätter für Augenheilkunde, Stuttgart, 1873. * ''Das Wasser als Träger des Choleragiftes''. Küchenmeister’s Zeitschrift für Epidemiologie und öffentliche Gesundheitspflege, Darmstadt and Leipzig, 1874. * ''Einfluss der Concavgläser auf die Weiterentwicklung der Myopie''. Knapp’s Archiv für Augenheilkunde, Wiesbaden, XIV.

External links

*
''Carl Friedrich Richard Förster''
@

Who Named It ''Whonamedit?'' is an online English-language dictionary of medical eponyms and the people associated with their identification. Though it is a dictionary, many eponyms and persons are presented in extensive articles with comprehensive bibliograp ...

. {{DEFAULTSORT:Forster, Carl Friedrich Richard German ophthalmologists 1825 births 1902 deaths Academic staff of the University of Breslau Members of the Prussian House of Lords People from Leszno People from the Grand Duchy of Posen