With this article, we aimed to trace the evolution and impact of eye-related terms common in written English during the past 2 centuries by studying digital resources. Eye-related words and phrases (n-grams) occurring in English books at a frequency of 0.00001% for at least 25 years between 1790 and 2008 were identified from the Google n-gram database by searching for 254 strings such as eye or ophth. The first known English use of these n-grams was identified from historical articles and from multiple digital resources. Eye color was not commonly described as brown or green before 1840. Many common bigrams, such as bright eyes, suggested light emanating from the eyes, consistent with the extramission theory of vision. Based on word frequency, the impact of the revolutionary 1850 ophthalmoscope exceeded that of the stethoscope for 60 years. Glaucoma was not commonly written until the ophthalmoscope permitted visualization of the characteristic optic neuropathy. Green spectacles gave way during the early 1900s to dark glasses, subsequently renamed sunglasses. Until the mid-1900s, an eye surgeon was more often described as an oculist than an ophthalmologist, and inflamed eyes were said to experience ophthalmia more often than uveitis. Macular degeneration was rarely written about for more than a century after 1850 because it was labeled choroiditis. Of the 135 n-grams in the dictionary, an earlier written instance was identified in 92 cases (68%). Online databases of the written word reveal the origin and impact of many important vision concepts.
Christopher T. Leffler, MD, MPH; Stephen G. Schwartz, MD, MBA; Russell Stackhouse, MD; Byrd Davenport, MD; Karli Spetzler, MD
1. Department of Ophthalmology, Virginia Commonwealth University, Richmond, Virginia
2. Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Naples, Florida
A new approach to historical research traces the rise and fall of concepts by computational analysis of millions of documents. Based on approximately 4% of all books ever published, Google has created a database of the annual frequency of 1- to 5-word phrases, termedn-grams (eTable 1 in Supplement).1,2 We studied the database to gain insights about the history of vision-related concepts. In addition, we documented the earliest references in English to these terms by reviewing historical articles and online databases.
We began by downloading the English-language corpus of the Google n-gram database (eTable 1 in Supplement).1,2 For candidate n-grams related to eye diseases, symptoms, appearance, or treatments to be considered major, the n-gram frequency had to be greater than 0.00001% (10−7) for a 25-year period between 1790 and 2008. For the Google database, a high-frequency period began when the frequency was greater than the threshold for 4 of 5 consecutive years and ended when the frequency dropped to less than the threshold for 4 of 5 consecutive years.
For words with a medial s before 1820, the totals for the regular string plus the string with an f were combined (eg, oculist and oculift). As uppercase was frequently used in the middle of sentences, cases were combined before 1780 (eg, cataract and Cataract). Forms with the nonleading v written u were included (eg, evil eye and euil eye).
Candidate 1-grams and 2-grams were identified by mining the Google n-gram data. A file containing 254 eye-related root strings, such as eye, ophth, optom, ocul, optic, corne, and retin, was created based on ophthalmology texts and historical reviews. A Windows batch file program incorporating the findstr command was used to identify lines in the data files containing these strings, independent of case. The output files were manually reviewed to identify major unigrams. The 1-gram strings and the Google data files were inputted into the findstr command to identify candidate 2-grams. N-grams without eye-specific root strings (e.g., slit lamp) were manually evaluated. Candidate 3-grams and 4-grams were suggested using the BYU interface for American books in the Google data set (eTable 1 in Supplement).3 These n-grams still had to meet the same criteria to be considered major (>10−7 for 25 years in the English-language corpus).
The date of first word use was determined by historical articles and full-text searching of digital resources (eTable 1 in Supplement). We searched US newspaper databases, but these did not identify any first uses of ophthalmology words. Listings in Latin-to-English dictionaries were not counted as first uses of English words (eReferences in Supplement). Because the n-gram database is sparse before 1800, evidence of the earliest decade of frequent use for major terms was also sought in more complete early databases (eTable 1 inSupplement).4,5 Because the average book length before 1800 was 70 000 words,2 presence in 0.7% of books in a decade was considered evidence of a word frequency of 10−7.
The year of the first use is in regular script, while the decades of frequent use (>10−7) appear with a hyphen. Date ranges in brackets relate to the early English databases; those in parentheses relate to the Google database.4,5 For instance, purblind 1325,6 [1590-],-1970 means an instance was identified in 1325, and that purblind exceeded an estimated frequency of 10−7 beginning in the 1590s in early English books.5 In the Google database,2 purblind was used frequently (>10−7) by 1790 through a year in the 1970s. A long dash indicates that a word was frequent through 2008.
For centuries, the term blind [by 1470–] has implied poor vision, but not necessarily the absence of light perception (eTable 2 in Supplement). Patients have been described as blinde [by 1470–], purblind [1590-], or sightless [1790-]. Having weak, dim, blind, or unseeing eyes was common in the past (eReferences inSupplement). In the 19th and 20th centuries, people were born totally, almost, so, quite, mere, or nearly blind, or they became blind.
In 1587, English physician Anthony Hunton, MD (1560?-1624)7 translated the ophthalmic treatise of French royal surgeon Jacques Guillemeau (1550-1612).8 Hunton discussed both amaurosis (1810–), a medical term implying poor vision, and amblyopia (1860—), which often implied a lesser visual impairment (Figure 1).9 Hunton also discussed couching [1570-], strabismus, chemosis (1870–), mydriasis (1870—), myopia (1870—), trachoma (1880—), and proptosis (1950–).9 Hunton was one of the earliest English writers to review squint, glaucoma,11 and staphyloma (1870–) (eReferences in Supplement). A later edition used the modern spelling night blindness (1930—).12 Translation of another work by Guillemeau used the term ectropion (1900—).13
Long after his training under Georg Joseph Beer, MD, of Vienna (1763-1821),14 Scottish ophthalmologist William MacKenzie, MD (1791-1868),15 described asthenopia (1870–),16 which decades later was renamed eyestrain (1900–). In the early to mid-1800s, vision began to be more commonly characterized with reading tests, which evaluated the visual angle (1820–) (eReferences in Supplement). The most popular were the 1854 test types of Vienna ophthalmologist Eduard Jaeger, MD (1818-1884),17 the grandson of Beer. These are still used today to assess near vision (1870–).
In 1862, Herman Snellen, MD (1834-1908), working under Frans Cornelis Donders, MD (1818-1889), at the Netherlands Ophthalmic Hospital, published the acclaimed optotypes for testing distant vision (1870–) based on an objective standard (line thickness 1 minute of arc).18,19 However, visual acuity10 (1880—) was not commonly written for several decades, in part because Sehschärfe20,21 and gezichtsscherpte22 (literally vision sharpness) were translated as acuteness of vision23 (1870-; Figure 1; eReferences in Supplement).
In the modern era, visual defects (1930–), disturbances (1940—), impairment (1940—), or loss (1960—) result from eye trouble (1930–) and disease (1970—). Defective (1900–), poor (1940—), blurred (1950—), and tunnel (1950—) vision are surprisingly modern constructions (Figure 1; eReferences in Supplement). From the latter half of the 19th century, there has been interest in color-blindness (1870–) (also written colour-blindness, 1890-; or color blindness, 1900—) and color vision (1900—, eTable 2 in Supplement).
When viewed as a percentage of the common bigrams to describe eye appearance, blue eyes [1760–] have accounted for a stable one-third during the past 2 centuries (Figure 2). Bigrams for bright [1590–] and black [1730–] eyes faded in frequency, while those for brown (1840–) and green (1860–) eyes became common after 1840 (Figure 2).
Many common bigrams suggested light emanating from the eyes. There were brilliant, burning, fiery, glistening, glittering, glowing, light, and lustrous eyes. Commonly, eyes blazed, brightened, burned, gleamed, glistened, glittered, glowed, lighted, lit, shone, or sparkle(d), or they were flashing. Bigrams for blazing, bright, glaring, gleaming, shining, sparkling, and twinkling eyes occurred commonly in either order (eg, bright eyes, eyes bright). There was the bright, kindling, and sparkling eye; the eye(s) that flashed; and the beaming and flashing eye(s). These 44 bigrams represent close to 20% of the common bigrams relating to eye appearance. The prominence of these bigrams is consistent with the extramission theory, which states that vision involves light or energy emitted from the eyes.24 Adherents to this theory included some ancients, young children, and many modern adults.25
The importance of this concept is supported by (1) bigrams just below the threshold: inflamed, luminous, and radiant eyes, (2) the common expressions starry-eyed and twinkling of an eye [1560–], and (3) common bigrams noting the absence of the emission: dim, dull, and dark eyes. Other common bigrams suggest eye emission of energy or power: visual and eye contact (1960—), and the piercing, sharp, penetrating, and evil eye [1650–] (eTable 2 and eReferences in Supplement).
The pupil (1610) is from the Latin pupilla for female child or doll and is etymologically related to pupil to represent a student (eReferences in Supplement).6 This derivation arose from observation of one’s minified reflection when gazing at the pupil of another.6 Similarly, anisocoria and corectopia are derived from the Greek κóρη for girl, doll, or eye’s pupil.6
Throughout the 19th century, eye patients sought help from the oculist (1800–). Renaming the practitioner ophthalmologist26 (1900—) and calling the profession ophthalmology (1880—) did not begin in earnest until the 20th century. Oculist was written more often than ophthalmologist as recently as 1956 (Figure 3). The selection and sale of spectacles was generally handled by an optician. The optician with specialized training in refraction adopted the moniker optometrist only recently (Figure 3; eReferences in Supplement).
Spectacles and Refraction
Spectacles [1520–] were invented in the late 1200s, most likely in Italy. The devices were later known as glasses (1593), an eyeglass (1840—), and then eyeglasses (1880—). Spectacles for presbyopia (1870–) were known as a convex glass (1820–), then convex glasses (1860–), and finally reading glasses (1980—) (eReferences in Supplement). By 1784, Benjamin Franklin had invented double spectacles,27 but their popularity as the bifocal (1940—) came much later.
Spherocylindrical lenses to correct astigmatism were first described in 1827 by English astronomer George Airy (1801-1892),28 who attributed the term astigmatism29 (1860—) to William Whewell (eReferences inSupplement).
Being presbyopic and being farsighted (1890—)30,31 were considered equivalent. Donders distinguished presbyopia from what he called hypermetropia (1860–), consistent with his terminology for refractive errors, for example, ametropia (1880–) (eReferences in Supplement). In 1860, hypermetropia was used, along with Donders’ term emmetropic eye (1870–), by New York ophthalmologist Henry Drury Noyes, MD (1832-1900).32,33 German physiologist and physicist Hermann von Helmholtz (1821-1894)34 proposed the alternative term hyperopia (1890—).23 In 1860, London ophthalmologist John Soelberg Wells, MD (1824-1879), who trained with German ophthalmologist Albrecht von Graefe, MD (1828-1870), used hyperopia, which is now the more common term.35-37
Green spectacles (1830–) were popular in the 19th century. Dark glasses (1930—) became common a century later and were then renamed sunglasses (1950—) (eReferences in Supplement).
Strabismus and Eye Movements
For centuries, oculists have described squint [1570–] or strabismus (1840—).9 In 1683, William Briggs, MD (1650-1704),38 the English physician and anatomist, noted that being cross-eyed (1880—) caused double vision (1850—), later described as diplopia (1870—) or seeing double images (1880-). David Macbride of Ireland, who studied scurvy while a Royal Navy surgeon during the War of the Austrian Succession,39 wrote in 1772 of nystagmus (1870—) and photophobia (1850—).40 George Thomas Stevens, MD, PhD (1832-1921) a New York ophthalmologist and former Civil War surgeon,41 proposed the -phoria suffix in 1886 for a strabismus tendency, eg, heterophoria and exophoria (both 1890-),6 and the -tropia suffix for a manifest strabismus, eg, esotropia42 and exotropia (both 1960—).42 Ideally, treatment prevents amblyopia ex anopsia or a lazy eye, and it permits binocular (1860—) and stereoscopic vision (1930–), later known asstereopsis (1970—) (eReferences in Supplement).
Cornea and Cataracts
Eyes without adequate lachrymation (1850–) were said to have xerophthalmia (1930–) or dry eye (1810—). Conical cornea is now known as keratoconus (1980—).43 Although Donders coined aphakia, the adjectiveaphakic (1960—) came later. Cataract ([1750–],—) was by far the most commonly mentioned eye disorder (eReferences in Supplement). Cataract extraction (1960—) is now more often described as cataract surgery (1960—).
The 1850 presentation of the ophthalmoscope developed by von Helmholtz revolutionized understanding of both ophthalmic and systemic processes.34 The n-gram frequency analysis reflects the dramatic impact of the ophthalmoscope (1850—),44 which dwarfed that of the otoscope, and which for 60 years rivaled or exceeded the frequency of the stethoscope, considered a symbol of all of medicine.
The n-gram analysis showed that the development of the ophthalmoscope coincided with glaucoma (1860—) becoming a common eye disease (Figure 4). In English, glaucoma11 preceded the ophthalmoscope by centuries. At least from Hunton’s 1587 translation,9 glaucoma involved loss of vision, sometimes described with a greenish hue to the pupil. By the time of Mackenzie’s 1830 treatise, the term glaucoma was also associated with firmness of the eye.48 But this diagnosis was likely rare: glaucoma had a frequency in books of 1.9 × 10−8 prior to 1800 and 5.0 × 10−8 from 1800-1849.
The ophthalmoscope permitted observation of glaucomatous excavation of the optic disc. Based on the symptoms and signs, such as retinal arterial pulsations, von Graefe surmised that the intraocular pressure was elevated. He noted the effect of iridectomy (1860—), which became one of the most frequently described ophthalmic procedures for more than a century (Figure 4; eReferences in Supplement). Intraocular pressure, from von Graefe’s term intraoculare Druck,49 appeared in 1858 translations45 and reviews of his work including those by Mackenzie46 and by von Graefe himself.47 In 1868, Noyes reported on an early German tonometer50 (1960—,Figure 4).
Von Graefe advocated mapping the visual field (1860—,Figure 4). Peripheral vision (1960—) appeared in translations51 of his term peripherische Sehen.52 Blind spot (1870—) and scotoma (1880—) entered common parlance. The concept was not completely novel, as evidenced by the earlier field of vision (1820—) (eReferences in Supplement). Miotics for glaucoma followed: (1) eserine (1870–), later commonly called physostigmine (1900—), and (2) pilocarpine (1870—). The mid-1900s saw the popularity of treatment with topical epinephrine (1920—)53 and with Diamox (1950-),54 generically acetazolamide (1960—).55,56 After cataract, glaucoma continues to be the eye disease most commonly mentioned in books.
Ophthalmia and Uveitis
In the 19th century, the most common description of an inflamed red eye (1820—) was ophthalmia (1790—, Figure 5). In addition to treatment with leeches or bleeding, extracts of belladonna (1820—) or its principal ingredient, atropine (1860—), were used (eReferences in Supplement).
Before the ophthalmoscope, few oculists divided ophthalmia anatomically, for example, iritis(1820—), conjunctivitis(1850—), choroiditis57(1870-), and cyclitis(1870–;Figure 5 and Figure 6; eReferences in Supplement). Scottish ophthalmologist George C. Monteath, MD (1788-1828), who cofounded the Glasgow Eye Infirmary with Mackenzie, used keratitis(1870—), retinitis(1860—), and ophthalmoplegia(1890—) in his 1821 translation of Carl Weller’s treatise.30,61Mackenzie describedsympathetic ophthalmia62(1900–).
With the ability to see the fundus in 1850, a great splitting based on anatomic location accelerated. The aforementioned terms became common and additional terms were coined: keratoconjunctivitis(1950—) and chorioretinitis (1960—) (eReferences inSupplement). Von Graefe described iridocyclitis(1900—).58 Mackenzie discussed endophthalmitis(1970—).60 Today, inflammatory conditions are lumped together as uveitis(1940—, Figure 5), which appeared in reviews of Simeons’ 1828 work.59 Bibliographic mentions of ophthalmia exceeded those of uveitis as recently as 1967.
Retina and Optic Nerve
The earliest identified use of the term optic neuritis(1860—)63 was by English ophthalmologist Edward Hocken, MD (1820-1845).64 Donders coined the term retinitis pigmentosa(1950—).6 Some ophthalmic findings were renamed. The choked disc (1900-) became papilledema(1940—). Retrolental fibroplasia(1950-) became retinopathy of prematurity (1980—).
After the development of the ophthalmoscope in 1850, more than a century passed before the popularity of the German term drusen (1980—), used by Wells,65 and of the terms senile degeneration of the macula and macular degeneration (1970—) (eReferences inSupplement). Choroiditis was as common in books at the turn of the century as macular degenerationis today (Figure 6). Indeed, descriptions of senile choroiditis66 and guttate choroiditis67 are consistent with macular degeneration. By 1895, ophthalmologists began to realize that the “question of diagnosis between disseminated choroiditis and some changes of extensive colloid choroidal degeneration has been one of some difficulty.”67
Hocken used the term exophthalmic(1870-).68 Exophthalmic goitre(1870-), or goiter(1900-), is now known as thyroid ophthalmopathy(1970—). Injured eyes were removed by enucleation(1870—). The conventional view that Noyes was the first to speak of eyes being eviscerated69 (1940—) might be accurate because the first allusions to globe evisceration appeared in New York. Replacement was with an artificial eye (1860-), now more commonly known as a glass eye(1920-) (eReferences inSupplement).
Source of Word Origins
Of the 107 major unigrams, 5 (5%) were not in the dictionary6: Diamox, drusen, endophthalmitis, esotropia,and hyphema. Of the 135 frequent ophthalmic n-grams with origins in the dictionary,6 the sources of the earliest uses were the dictionary (43 cases, 32%),6 Google (59 cases, 44%),70,71 early English books (22 cases, 16%),5 Gale 18th century collections (5 cases, 4%),4 the Internet Archive (3 cases, 2%),72 and historical articles (3 cases, 2%).
This study of English-language databases and documents traced the evolution of major eye-related concepts over the past few centuries. The immediate impact of the 1850 ophthalmoscope in the written record and on the understanding of glaucoma is clear from the analysis. Even readers of historical works might be surprised that brown eyes, ophthalmologist, macular degeneration, blurred vision, eye drops, and uveitis only recently became frequently used terms. More than two-thirds of the time, words were identified in texts earlier than the first date of use in standard reference works.
The used standard for inclusion of terms, being mentioned in books for 25 years at a frequency of greater than 10−7, was an arbitrary, but objective, metric. We included topics that faded in importance such as green spectacles or cyclitis.
Several physicians played a role in recording multiple eye-related n-grams. The compilations of European ophthalmic knowledge by Guillemeau and Weller were translated into English by Hunton and Monteath, respectively. Wells and Noyes studied on the continent and were early adopters of its terminology. Mackenzie, Donders, and Stevens tended to coin ophthalmic terms. Von Graefe’s language was adapted owing to his major scholarly and scientific contributions.
The study of word frequencies in books has been dubbed culturomics.1 This term is a misnomer. Books reflect only one aspect of culture and do not cover other written work, nonwritten media, and the spoken word. For instance, eye twitching is a common Internet search73 but was not commonly used by authors, whose emphasis might differ from that of patients.
The Oxford English Dictionary contained 95% of the ophthalmic 1-grams. This result is similar to those for the English language overall1: an 85% inclusion in the dictionary for frequencies between 10−7 and 10−6 and an inclusion rate close to 100% for words greater than a frequency of 10−6. Of the 135 n-grams in the Oxford English Dictionary, an earlier written instance could be identified in 92 cases (68%). It is likely that even earlier English examples will be identified as additional documents are digitized.
This study had limitations. The data-mining procedure identified ophthalmic terms common after 1790 because the Google n-gram data are sparse before that time. Mining robust databases covering 1470-1790 might uncover archaic ophthalmic terms. The study primarily focused on 1-grams and 2-grams. Treatment of higher-order n-grams cannot be considered comprehensive because these were suggested by an interface for US books as opposed to mining the complete English-language corpus. Some words, such as glasses, cataract, couching, and spectacles, also have nonophthalmic meanings. The reference of word origin was the first ophthalmic listing that could be found, but the period of high frequency reflects all senses of the word. The books scanned by Google from university libraries may not be truly representative of all English books for a given period.1
Michel JB, Shen YK, Aiden AP, et al; Google Books Team. Quantitative analysis of culture using millions of digitized books.Science. 2011;331(6014):176-182.
Ngram viewer. Google.http://books.google.com.proxy.library.vcu.edu/ngrams. Accessed June 30, 2012.
Google books.http://googlebooks.byu.edu. Accessed June 30, 2012.
Gale Cengage Learning Eighteenth Century Collections Online.http://www.gale.cengage.com. Accessed June 30, 2012.
Early English Books Online Text Creation Partnership.http://quod.lib.umich.edu.proxy.library.vcu.edu/e/eebogroup/. Accessed June 30, 2012.
The Oxford English Dictionary Online.http://http://www.oed.com. December 2011 update. Accessed March 1, 2012.
Sorsby A. A late sixteenth century ophthalmic book in English.Br J Ophthalmol. 1932;16(8):508-509.
Ruhrah J. Jacques Guillemeau: 1550-1612.Arch Pediatr Adolesc Med. 1931;41(5):1172-1178.
Guillemeau J, Hunton A.A Worthy Treatise of the Eyes: Contayning the Knowledge and Cure of One Hundred and Thirtene Diseases.London, England: Waldegraue; 1587:1-189.
Hulke JW. On enucleation of the eyeball.BMJ. 1866;1:89-91.
Hyperius A, Vaux R.Two Common Places Taken Out of Andreas Hyperius, a Learned Diuine.London, England: Wolfe; 1581:34.
Read W.A Short but Exact Account of All the Diseases Incident to the Eyes.2nd ed. London, England: J Baker; 1710:61.
Guillemeau J.The Frenche Chirurgerye, or All the Manualle Operations of Chirurgerye.Dordrecht, the Netherlands: Canin, 1597.
Albert DM, Blodi FC. Georg Joseph Beer: a review of his life and contributions.Doc Ophthalmol. 1988;68(1-2):79-103.
Fergus F. British masters of ophthalmology series, I: sketch of the life of William McKenzie, MD (1791-1868), her majesty’s oculist for Scotland, surgeon of the Glasgow Eye Infirmary.Br J Ophthalmol. 1917;1(3):141-147.
MacKenzie W. On asthenopia or weak-sightedness.Edinburgh J Med Surg.1843;60:73-103.
Runge PE. Eduard Jaeger’s test-types (Schrift-Scalen) and the historical development of vision tests.Trans Am Ophthalmol Soc. 2000;98:375-438.
Snyder C. Herman Snellen and V=d/D.Arch Ophthalmol. 1962;68(4):571-573.
Pfeiffer RL. Frans Cornelis Donders: Dutch physiologist and ophthalmologist.Bull N Y Acad Med. 1936;12(10):566-581.
von Graefe A. Kleinere Mittheilungen.Graefes Arch Clin Exp Ophthalmol. 1855;1:296.
Donders FC.Astigmatismus und Cylindrische Glaeser.Berlin, Germany: Verlag von Hermann Peters; 1862.
Snellen H.Letterproeven tot Bepaling der Gezichtsscherpte.Utrecht, the Netherlands: Weyers; 1862.
Donders FC, Moore WD.On the Anomalies of Refraction and Accommodation of the Eye.London, England: New Sydenham Society; 1864:188.
Gordon BL. The problem of the crystalline lens.Arch Ophthalmol. 1935;14(5):774-788.
Winer GA, Cottrell JE, Gregg V, Fournier JS, Bica LA. Fundamentally misunderstanding visual perception: adults’ belief in visual emissions.Am Psychol. 2002;57(6-7):417-424.
Vetch J.A Practical Treatise on the Diseases of the Eye.London, England: Whittaker; 1820:21.
Snyder C. Doctor Franklin’s double spectacles.Arch Ophthalmol. 1966;75(5):733-735.
Searle A. George Biddell Airy.Proc Am Acad Arts Sci. 1891;27:446-448.
Airy GB. Examination paper for Smith’s prizes. In:The Cambridge University Calendar for the Year.Cambridge, England: J Deighton; 1831:401-405.
Weller CH, Monteath GC.A Manual of the Diseases of the Human Eye.Vol 1. Glasgow, Scotland: Reid & Henderson; 1821:80-266.
Guthrie GJ.A Treatise on the Operations for the Formation of an Artificial Pupil.London, England: Longman, Hurst, Rees, Orme and Brown; 1819:101.
Noyes HD. Ophthalmology.Am Med Times.1860;1:300-302.
Bull CS. In memoriam: Henry D Noyes.Trans Am Ophthalmol Soc. 1902;9:414–422.
Schett A. The discovery of the ophthalmoscope by Herman von Helmholtz (1824-1894).Strabismus. 1999;7(4):241-244.
Wells JS. Paralytic affections of the muscles of the eye.Ophthalmic Hosp Rep J Royal London Ophthalmic Hosp. 1860;2:284-309.
Shastid TH. Ophthalmic jurisprudence. In: Soelberg Wells J.The American Encyclopedia and Dictionary of Ophthalmology. Vol 18. Chicago, IL: Cleveland Press. 1921:14012.
Albrecht von Graefe 1828-1870.Br J Ophthalmol. 1928;12(10):531.
James RR. William Briggs, M.D. (1650-1704).Br J Ophthalmol. 1932;16(6):360-368.
Fitzgerald TW.Ireland and Her People.Vol 3. Chicago, IL: Fitzgerald Book Co; 1910:121.
Macbride D.A Methodical Introduction to the Theory and Practice of Physic.London, England: W Strahan; 1772:191-194.
Duane A. George Thomas Stevens, MD, PhD.Trans Am Ophthalmol Soc. 1921;19:14-19.
Gould GM.A New Medical Dictionary.Philadelphia, PA: Blakiston; 1891:418.
Williams E. Keratoconus.Cincinnati Med Observer. 1856;1(3):97-108.
Wells TS. Some account of a new ophthalmoscope.Med Times Gazette.1853;7:264.
Strothotte A. Translation of Prof Graefe’s memorial to the French Academy, on glaucoma.Cincinnati Lancet Observer. 1858;1(11):641-658.
Jones TW, Mackenzie W. On the operation of iridectomy, or excision of a piece of the iris, as recommended by Dr Graefe, of Berlin, as a means of cure in various diseases of the eyes, especially chronic iritis, irido-choroiditis, and glaucoma.Am J Med Sci. 1858;36:257-262.
Von Graefe A. On Dr Von Graefe’s operation for glaucoma.Half-Yearly Abstract Med Sci. 1858;28:160-161.
Sorsby A. Hardness of the eye: an historical note.Br J Ophthalmol. 1932;16(5):292-295.
Von Graefe A. Ueber die Coremorphosis als Mittel gegen chronische Iritis und Iridochoroiditis.Arch Ophthalmol. 1856;2(2):202-257.
Noyes HD, Hammond W, Dunster ES. Reports on progress of medicine and surgery.New York Med J. 1868;6:464-469.
Von Graefe A, Windsor T.Three Memoirs on Iridectomy in Certain Forms of Iritis, Choroiditis, and Glaucoma.London, England: The New Sydenham Society; 1859:360.
Von Graefe A. Weitere klinische Bemerkungen über Glaucom, glaucomatöse Krankheiten und über die Heilwirkung der Iridectomie.Archiv für Ophthalmologie. 1858;4(2):127-161.
Vaughan D, Shaffer R, Riegelman S. A new stabilized form of epinephrine for the treatment of open-angle glaucoma.Arch Ophthalmol. 1961;66(2):232-235.
Maren TH. Pharmacological and renal effects of diamox (6063), a new carbonic anhydrase inhibitor.Trans N Y Acad Sci. 1952;15(2):53.
Acetazolamide in glaucoma.BMJ. 1955;2(4967):479-481.
Lowe RF. A history of primary angle closure glaucoma.Surv Ophthalmol. 1995;40(2):163-170.
Travers B.A Synopsis of Diseases of the Eye, and Their Treatment.London, England: Longman; 1820:132.
Von Graefe A. On iridectomy in iritis, irido-choroiditis, and glaucoma.Med Times Gazette. 1858;447-448.
Simeons. On chronic inflammation of the uvea.Lancet. 1829;11(285):619-620.
Mackenzie W.So-Called Diphtheritic Ophthalmia.No. 10. Vol 2. London, England: Royal London Ophthalmic Hospital; 1860:175.
Leffler CT, Randolph J, Stackhouse R, Davenport B, Spetzler K. Monteath’s translation of Weller: an underappreciated trove of ophthalmology lexicon.Arch Ophthalmol. 2012;130(10):1356-1357.
Mackenzie W. Clinical lectures by Dr Mackenzie: iritis sympathetica.London Medical Gazette. September 29, 1838:91-94.
Hocken E. Sketch of the pathology of amaurosis.London Medical Gazette. March 20, 1840:940-943.
Hunter RA, Thornton JL. Edward Octavius Hocken (1820-1845); life and writings of a forgotten man.Med Hist. 1958;2(1):57-61.
Wells JS.A Treatise on the Diseases of the Eye.2nd ed. London, England: John Churchill; 1870:371.
Nettleship E, Thompson W.The Student’s Guide to Diseases of the Eye.3rd ed. Philadelphia, PA: Lea Brothers and Co; 1887:216-217.
Carpenter JT. Extensive colloid changes in the choroid, with report of cases.JAMA. 1895;25:737-739.
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