Ophthalmological Observations Made During the Mid-19th-Century EuropeanEncounter With Africa

  European travelers in Africa in the mid-19th century encountered environmentsquite unlike those of their native lands. These provided many new and unanticipatedhealth challenges. The ophthalmological consequences of exposure to such climates,as recorded incidentally in travelogues, are of potential interest. In thisarticle, the almostcontemporaneous narratives of 3 travelers with considerablemedical training, David Livingstone and his sometime companion John Kirk,who journeyed in southern Africa, and Gustav Nachtigal, who traveled in northernAfrica, are examined for information on ophthalmological problems, both observedand personally experienced. This affords an opportunity to compare observationsmade in Saharan and sub-Saharan Africa.

At present I'm spending time with good old Livingstone in darkestAfrica. The monotony of his endless and virtually pointless journey, the constantobsession with barometric pressure and meals that rarely arrive, and the silent,calm unfolding of vast landscapes—all this makes for truly wonderfulreading. ^{1(p 8)}

The French author Alphonse Daudet (1840-1897) perfectly captures thetedium and excitement, the attraction and repulsion, of reading through DavidLivingstone's accounts of his African journeys. Similar feelings might bearoused by reading the lengthy travel narratives in which other 19th-centuryEuropeans recorded their encounters with Africa. From within these travelogues,however, one may excavate much material of interest to students of history,geography, ethnography, meteorology, geology, botany, zoology, and medicine—even,as this article hopes to demonstrate, ophthalmology.

David Livingstone (Figure 1)made 3 major expeditions in southern Africa during the last 20 years of hislife: the Transcontinental Expedition of 1853-1856, the Zambesi Expeditionof 1858-1864, and the final journey of 1866-1873, the ostensible aim of whichwas to search for the sources of the Nile River. These travels passed throughthe territories of modern Botswana, Namibia, Angola, Zambia, Malawi, Mozambique,Tanzania, and Zaire. During these years, Livingstone kept daily journals thatgave rise to 3 major works: Missionary Travels and Researchesin South Africa² (1857), Narrative of an Expedition to the Zambesi and Its Tributaries³ (1865), and The Last Journals ofDavid Livingstone in Central Africa, published posthumously in 1874by Livingstone's friend Horace Waller.⁴ Inaddition to these volumes, which total more than 750 000 words,⁵ Livingstone maintained a large correspondence, muchof it now published.^6-13 Althoughhis life and career have been endlessly anatomized since his death, it isthese rich primary sources that form the basis for this account.

Most of Livingstone's travels were without European companions; thepropensity for European fellow travelers to quarrel in Africa (eg, James Richardsonand Heinrich Barth; John Hanning Speke and Sir Richard Francis Burton^{14(pp 26,29,30)}) was also true of Livingstone.The partial exception to this was the Zambesi Expedition, sponsored by theBritish government; almost throughout this expedition, Livingstone was accompaniedby John Kirk (Figure 2),^15,16 who also kept a daily journal. However,this was published nearly 100 years later.^17,18 CharlesMeller also accompanied the Zambesi Expedition in its later stages^15,16 and contributed 2 short articlesto the contemporary medical press,^19,20 butwhether he kept a journal (as would seem likely) and if so whether it is extantis currently unknown. He certainly made drawings, 1 of which was used by Livingstone.^{4(vol 1:p 110)}

Livingstone's principal medical concern throughout his travels was "Africanfever," probably due to malaria.^15,16,21,22 Henoticed that the systemic effects of fever could also involve the eyes, whichoften became "suffused" during bouts of fever.^3(p74) When in 1867 he was desperately ill with fever and without medicines,experiencing "pneumonia of right lung, and I cough all day and all night:sputa rust of iron and bloody,"^{4(vol 2:p 2)} he noted, "[I]f I look at any piece of wood, the bark seems coveredover with figures and faces of men, and they remain, though I look away andturn to the same spot again."^{4(vol 2:p 2),13(p 69)}Presumably these wereeither visual hallucinations or palinopsia occurring in the context of febrileillness.

Livingstone described an illness experienced by Kirk in June 1860 thatis also relevant to fever:

Here we remained a couple of days in consequence of the severeillness of Dr Kirk. He had several times been attacked by fever; . . . hehad been trying different medicines of reputed efficacy with a view to ascertainwhether other combinations might not be superior to the preparation we generallyused; in halting by this water, he suddenly became blind, and unable to standfrom faintness. The men, with great alacrity, prepared a grassqy bed, on whichwe laid our companion, with the sad forebodings which only those who havetended the sick in a wild country can realize. We feared that in experimentinghe had overdrugged himself; but we gave him a dose of our fever pills; onthe third day he rode the one of the two donkeys . . . and on the sixth dayhe marched as well as any of us.^{3(p 207),18(pp 172-173)}

Regrettably we have no account of this incident from Kirk because hisjournal for this period was lost in an accident at Kebrabassa Rapids a fewweeks later.

Regarding ophthalmological problems per se, we might expect Livingstone,traveling as he did in regions where leprosy, smallpox, and trachoma wereprevalent, to have made some pertinent observations. Indeed, as early as 1850,before his major explorations got under way, he had noted the similarity betweenthe experimental eye disease in dogs given a diet of wheat gluten, starch,and sugar or olive oil, reported by the French physiologist FrançoisMagendie in 1816, and the blinding corneal disease seen in malnourished tribespeople:

The chief vegetable food is the manioc and lotsa [Pennisetum typhoideum] meal. These contain a very large proportionof starch, and when eaten alone for any length of time produce most distressingheartburn. As we ourselves experienced in coming north, they also cause aweakness of vision, which occurs in the case of animals fed on pure glutenor amyllaceous matter only. I now discovered that when these starchy substancesare eaten along with a proportion of ground-nuts, which contain a considerablequantity of oil, no injurious effects follow.^{2(pp 389, 431)}

This was probably xerophthalmia from vitamin A deficiency.^{23(p 380)}

Ophthalmia is mentioned by Livingstone several times (it has its ownsubheading in chapter 6 of Missionary Travels and Researchesin South Africa); he himself experienced "a touch of it," apparentlycaused by the dust created during a march.^{4(vol 2:p 154)} However, of greater importance to public health was theepidemic form of ophthalmia: "[E]very year the period preceding the rainsis marked by some sort of epidemic. Sometimes it is general ophthalmia, resemblingclosely the Egyptian."^{2(p 113)}

At Libonta, in December 1853, "much fever prevailed and ophthalmia wasrife, as is generally the case before the rains begin."^2(p217) Perhaps taking up Livingstone's theme, contemporaries believed"ophthalmia very prevalent" in Africa.^{24(p 248)}

Livingstone also described the indigenous treatment of ophthalmia:

In ophthalmia the doctors cup on the temples, and apply to theeyes the pungent smoke of certain roots, the patient at the same time takingstrong draughts of it up his nostrils. Cupping is performed with the hornof a goat or antelope, having a little hole pierced in the small end. In somecases a piece of wax is attached, and a temporary hole made through it tothe horn. When the air is well withdrawn, and kept out by touching the orificeat every inspiration with the point of the tongue, the wax is at last pressedtogether with the teeth, and the little hole in it closed up, leaving a vacuumwithin the horn for the blood to flow from the already scarified parts. .. . the doctor . . . by separating the fibrine [sic]from the blood in a basin of water by his side, and exhibiting it, pretendsthat he has extracted something more than blood. He can thus explain the rationaleof the cure by his own art, and the ocular demonstration given is well appreciated.^{2(p 114)}

An almost identical description is given in a passage written almost10 years later when Livingstone was traveling farther north and east. Thistime the surgeon was a woman, the patient her own child; in addition, "aftercupping her child's temples for sore eyes, [she] threw the blood over theroof of her hut as a charm."^{4(vol 1:p 223)} Native understanding of the possible causes of eye inflammation includedthe "mere sight" of an alligator^{2(p 222)} and drops of a clear fluid distilled by a "curious insect" on treesof the fig family.^2(p358)

In September 1866, Livingstone reached a village where "[t]he headmanhad been suffering from sore eyes for four months, and pressed me to stopand give him medicine, which I did."^{4(vol 1:p 98)} Regrettably, Livingstone does not mention what treatmenthe gave nor what effect it had. Likewise, he cured Señor Joao of Portugalof his eye problem, "inflammation of the choroid," which developed after carryingthe image of the Virgin Mary in a procession.^{11(p 163)}

It is difficult to extrapolate from Livingstone's 19th-century diseasecategories to our own when considering what exactly he meant by "ophthalmia."Generally, 3 broad categories of ophthalmia were recognized at this time:catarrhal, purulent, and sympathetic.^{25(pp 408,409)} Catarrhal ophthalmia probably corresponds to acute conjunctivitis,presumably what Livingstone had "a touch of" during his march, whereas purulentophthalmia, sometimes called Egyptian ophthalmia, was known to be contagious—commonlyoccurring in overcrowded circumstances; perhaps related to intense heat, glare,and high winds; and sometimes causing blindness. This condition was presumablybacterial conjunctivitis and may coincide with Livingstone's "epidemic ophthalmia."However, only once is a man "blind from ophthalmia" mentioned.^{4(vol 2:pp 200)}

Blind individuals are infrequently mentioned in Livingstone's narrative,and it is the social consequences of visual loss that draw his attention ratherthan its medical causes: "The elder brother of Sechele's father, becomingblind, gave over the chieftainship to Sechele's father."^{2(p 39)} However, blindness was not always an insurmountable disadvantage:"[A]n ugly but rich old fellow, who was so blind that a servant had to leadhim along the path" was able to marry young and pretty wives, much to thechagrin of younger, poorer, and sighted males.^{3(p 284)} The blind might be recognized simply from their behavior: a "poorblind woman, thinking we were Mazitu [a tribe of marauders], rushed off infront of us with outspread arms, lifting the feet high, in the manner peculiarto those who have lost their sight. . . . "^{3(p 505)} A similar description is given of the running of a buffalo thatapparently had ophthalmia.^{2(p 119)} A1-eyed chief was also encountered, but no cause was stated.^{4(vol 1:p 112)} The paucity of references to blindness may not be a truereflection of its frequency; in a lengthy footnote,^{2(pp 345,346)} Livingstone gives details from the 1854 census for the districtof Gulongo Alto in Portuguese Angola, in which there were reportedly 54 blindmen and women among a population totaling 40 797 (0.1%).

Nowhere does Livingstone discuss the causes of blindness, but possibilitiessuch as smallpox and leprosy spring to mind. He mentions a disease, probablysmallpox, that "comes every three or four years, and kills many of the people."^{4(vol 2:p 28)} Livingstone thought that thisdisease was more common on the African coast^{2(p112, 431)4(vol 2:p 166)} and wasacquired from Arab traders,^{2(p 114)} someof whom died from the condition in Africa along with a "loathsome skin disease,"^{4(vol 1:p 330)} presumably syphilis. On theZambesi Expedition, Kirk observed that smallpox was very common and had thevaccine sent by a colleague in Scotland, the plan being to vaccinate a cowand then use the cow as a source of further material for vaccination.¹⁵ Although he did manage to vaccinate some individuals,the vaccine started to become inert before its administration,^{17(pp 117,327,399,400)} a problem that dated back to Edward Jenner and continuedwell into the 20th century.¹⁵

Leprosy is another possible cause of visual loss, and this disease wascertainly encountered by Livingstone.^{2(p 519)}, ^{4(vol 2: pp 40,41)11(pp 100,186,197)} One of his closest allies,the chief Sekeletu, had it: "[H]is face was only slightly disfigured by thethickening of the skin in parts," but this case was apparently without ocularinvolvement.^{3(p 274)} No descriptionsthat might be consistent with trachoma or onchocerciasis can be found in Livingstone'sworks, nor any mention of cataracts, although there is 1 mention of an "insectin the aqueous chamber."^{4(vol 2:p 233)}

When describing the salubrity of the southern African climate, Livingstoneassured his readers, "[Y]ou may sleep out at night, looking up to the moontill you fall asleep, without a thought or sign of moon-blindness."^{2(p 117)} The exact nature of this moon-blindnessis unclear, but a curious incident is reported at Tette in 1860, which mayshed some light on it:

Four or five of our men were affected with moon-blindness atTette; though they had not slept out of doors there, they became so blindthat their comrades had to guide their hands to the general dish of food;the affection is unknown in their own country. When our posterity shall havediscovered what it is which, distinct from foul smells, causes fever, andwhat, apart from the moon, causes men to be moon-struck, they will pity ourdulness [sic] of perception.^{3(p 176)}

Peculiarly, no mention of this alarming occurrence appears in the relevantjournal.¹¹ It took place when some of the Makololotribesmen who had traveled across Africa with Livingstone (1853-1856), andthen waited at Tette for his return from furlough in Great Britain to guidethem back to their homeland, were on the point of departure. Having settledfor 4 years in the new location, many had developed commercial interests andtaken new wives; hence, there was understandable reluctance to go, and manyabsconded from Livingstone's party when he did set off.^{11(pp 164-167, 169, 249-252)} Evidently men so blind that their hands hadto be guided to their food could not travel across the terrain of Africa.One wonders if this was a functional illness.

Livingstone also mentions a phenomenon called stone-blindness:

"[Every flash of the intensely vivid lightning leaves you withthe impression of stone-blindness^{2(p 124)}. . . . the intervals between the flashes [of sheet lightning] wereso densely dark as to convey the idea of stone-blindness."^{2(p 441)}

The implication is one of complete blindness, as in the axiom "Thereare no such stone-blind men as those who will not see" (as in Charles Dickens'novel of 1857, Little Dorrit^{26(pp 274,275)}), which is distinct from partial or sand-blindness, anaffliction experienced by Old Gobbo in Shakespeare's TheMerchant of Venice.^{27(p 197)}

Although not described in detail, surgical procedures seem to have beenperformed by Livingstone and Kirk. When listing his instruments at the outsetof his journey from Loanda on the western coast of Africa, Livingstone mentionsonly a sextant, chronometer watch, thermometer, compass, and telescope,^{2(p 201)} but during the subsequent rainy seasonhe reports that the "surgical instruments become all rusty."^{2(p 261)} Whether surgery included cataract extraction is not clear. Kirkreported on August 7, 1863, that "the Banyan's eye on which I operated hasgone wrong,"^{17(p 528)} but no detailsof the procedure are given. One surgical operation lead to unexpected ophthalmologicalcomplications; when asked by a young woman to excise a "large cartilaginoustumour between the bones of the fore-arm, which, as it gradually enlarged,so distended the muscles as to render her unable to work,"^{2(p 417)} Livingstone undertook the procedure (having first obtained theconsent of the husband). While removing the tumor, "one of the small arteriessquirted some blood into my eye,"^{2(p 417)} an accident that unwittingly rendered the explorer a blood relationof the patient.

Ocular trauma was a consequence of the long grasses, through which theexpeditions often passed, rubbing the eyes. ^{2(p 395),4(vol 1:p 290)} Livingstonehimself sustained an accident to one of his eyes by a blow from a branch whenpassing through a forest.^2(p390) Otherplants could also prove hazardous, such as a species of Euphorbia that "when wounded" exuded a milky juice that could endangerthe eyes.^{11(pp 89,98)} One tribewas "much addicted to smoking the mutokwane (Cannabis sativa)," and although Livingstone never tried it, he was able to reportthe effects it sometimes induced: "Some view everything as if looking in throughthe wide end of a telescope, and others, in passing over a straw, lift uptheir feet as if about to cross the trunk of a tree."^{2(p 464)} These metamorphopsias (micropsia and macropsia) are reminiscentof some of Alice's experiences in Wonderland.

Insects too could be hazardous. Midges were sometimes so numerous thatthe eyes and mouth had to be kept closed,^{3(p 373)} and one particular hornet apparently tried to inflict its stingnear the eye.^{2(p 426)}

Several individuals are mentioned with squint.^{2(p 238)4(vol 1: pp 25, 197)} Thechief Casembe had "an outward squint in each eye,"^{4(vol 1:pp 250,264)} and the Arab Theni bin Suellim had a "disagreeableoutward squint of the right eye."^{4(vol2:p 10)} Moenempanda, Casembe's brother, had a "defect in his eyes, whichmakes him keep them half shut or squinting."^{4(vol 1:p 304)} Albinos were noted to be uncommon; Livingstone thoughtthat they were murdered but did observe 1 boy: "The pupil of the eye was ofa pink colour, and the eye itself was unsteady in vision."^{2(p 493)} This unsteadiness may perhaps represent a description of p endularnystagmus.

Gustav Nachtigal (Figure 3)made his African odyssey almost contemporaneously with Livingstone's lastjourney. He had come to northern Africa from Germany in 1862 when pulmonaryhemorrhages suggested that he had tuberculosis, an illness that had previouslykilled his father and a brother.^28,29 Hishopes of recovering his failing health in the warmer and drier climate werefulfilled, first in Algiers and then in Tunis, where he acted as physicianto the bey. On the threshold of returning to Germany, the opportunity arosefor extensive travel in the interior of Africa. Nachtigal's 5-year journey(1869-1874) followed a commission to deliver gifts from Kaiser Wilhelm ofPrussia to the sultan of Borno, a state on the shores of Lake Chad. It eventuallytook him more than 10 000 kilometers through territories now within theborders of modern Libya, Chad, Niger, Nigeria, Cameroon, Sudan, and Egypt.He kept a daily journal that was subsequently published in 3 volumes as Sahara und Sudan. Some 100 years later, this was translatedinto English as Sahara and Sudan, in 4 volumes.³⁰ Like Livingstone's books and journals, Nachtigal'swork is a rich resource for scholars of African history. Of particular pertinenceto this article, Nachtigal's credentials as an informed observer of ophthalmologicalconditions are strong. He had received excellent clinical training in Germany,including a period with Rudolf Virchow in Würzburg; although no detailsof specific ophthalmological training survive,³¹ hedid claim a particular interest in eye diseases. From 1867 onward, prior toundertaking his journey, he made inquiries about the possibility of returningto Germany as an eye specialist.^{30(vol1:p 7)} Perhaps his nearsightedness, causing incapacity without glasses,^{30(vol 3:p 292)} enabled him to empathize withpeople who were visually impaired.

Nachtigal devoted parts of chapters in his narrative to diseases, andspecific reference is made to ophthalmological conditions. For example, inthe desert in Fezzan (southern Libya),

Next to rheumatism . . . and chronic digestive disturbances,inflammations of the outer structure of the eye with their sequelae make themost important contribution to the list of diseases. Affections of the innereye, cataract and amaurosis, affections of the retina and the choroid membrane,of the optical nerve and the vitreous humour, are not exactly numerous, butthe number of people with their cornea and conjunctiva intact is still smaller.^{30(vol 1:p 138)}

In Bornu, on the shores of Lake Chad,

Ailments of the conjunctiva and cornea were of course predominant.Simple catarrh of the conjunctiva, proliferation of the conjunctiva to themost enormous extent, scarred contractions with their secondary conditions,fresh and cicatrised circumscribed corneal ulcers, general inflammation andopacity of the cornea, perforations or complete destruction of the corneawith protruding iris, were of such a frequency that the countries of the northcoast of Africa, notorious with us on account of their eye ailments, couldsustain no comparison with it.^{30(vol 3:p 201)}

In Wadai, further east,

[E]yeballs destroyed by smallpox, cataracts and glaucoma, diseasesof the conjunctiva, inflammation and ulcers of the cornea . . . formed thegreater part of the illnesses which came to me for treatment.^{30(vol 4:p 58)}

In addition to encounters with and reports of blind individuals,^{30(vol 3: pp 304,310,337,417: vol 4: pp 233, 315)} many 1-eyed or "half-blind" people are also mentioned.^{30(vol 2 pp 31,40,99,101, 304, 346)}In Borku, Nachtigal states,

I went . . . to Yin, curious to get to know this so-called Beledel-Amian, that is literally the village of the blind, a designation the originof which I was unable to discover.^{30(vol2:p 369)}

Inflammation of the eyes ascribed to the effects of sand-laden windsin the desert was a common affliction for both Nachtigal^{30(vol pp 47, 211, 213,215, 216, 327; vol 2: pp 361, 363)} and those travelingwith him,^{30vol 1: p 65; vol 2; p 42; vol4 p 106)} bandaging. Rubbing painful eyes might also lead to transmissionof diseases of the eyelids and conjunctiva. Antimony powder, or kohol, wasused by Nachtigal and local healers for the treatment of ophthalmia, for examplein Tibesti.^{30(vol 1:pp 193,436)} Otherindigenous remedies mentioned for eye disease include a powder mixed fromsugar candy, myrrh, and raven's bile.^{30(vol 1:p 138)} In Darfur, rancid butter "had a reputation as an outstandingremedy for eye diseases."^{30(vol 4:p 340)} At their request, Nachtigal attempted to treat the illnesses of thelocals:^{30(vol 1: p308; vol 3: p 243)}

My medical efforts were limited almost entirely to combattingfresh inflammations of the conjunctiva and cornea—only some few timesdid I find opportunity for iridectomy—and I achieved my chief successesin dealing with purulent eye inflammations of a specifically contagious character,which generally had already destroyed the one eye, and where I then succeededby energetic action in saving the other.^{30(vol 3:p 201,202)}

That blindness was often a result of suppuration is clear.^{30(vol 3:p 436)} In Kuka, the capital of Bornu, where Nachtigal stayed on3 occasions totaling several months,²⁷ blindpeople were evident in "unbelievable number"^{30(vol 2:p 160)}:

The innumerable blind people, whose eyeballs had decayed to themost pitiable stumps, and who nevertheless were still seeking medical aid,were nearly always the victims of purulent inflammations of the conjunctivaof a specifically infectious character, and most of the completely opaquecorneas evidently resulted from smallpox.^{30(vol 3:p 201)}

That smallpox was frequently to blame for "destroyed or darkened corneas"is suggested elsewhere.^{30(vol 1:p 138)} UnlikeLivingstone, Nachtigal implies that smallpox was more prevalent in the interiorof Africa than on the coast.^{30(vol 1:p 133; vol 3 p 203)}

Leprosy was also common, discoloration and atrophy of the skin beingthe most frequent manifestation,²⁹ althoughit might have accounted for some of the corneal ulceration Nachtigal saw.Glaucoma is also mentioned.^{30(vol 4:pp 58,315)}

Ritual blinding was a feature of political life in some of the statesNachtigal visited. For example, in Bagirmi,

[I]t is the first concern of the ruler on ascending the throneto make his brothers unfit to exercise kingly authority by mutilating them,for in Bagirmi, as in most of the other Sudan countries, custom requires thatthe king be unblemished physically as well as intellectually. As in Wadai,blinding has been the chosen mutilation, but it is applied in a more humaneway than in the neighbouring country, in that the cruel operation is limitedto one eye.^{30(vol 3:p 327)}

In Wadai, the melancholy task of blinding fell to the head chief ofthe smiths (sultan el-haddadin), a man who had tobe well read in the Qur'an and who was also the physician for the whole royalfamily. Here, nephews and cousins as well as brothers are stated to be candidatesfor blinding.^{30(vol 4:pp 175,179)} Boilingbutter was used for blinding in Bagirmi,^{30(vol 3:p 412)} whereas in neighbouring Wadai a hot iron was passed overthe eyes, a custom apparently dating from the beginning of the 19th century.^{30(vol 4:pp 174,175)} In some traditional Africansocieties, it is still the blacksmith who performs surgical procedures suchas circumcision.^{32(p 141)}

Although kings had to be "unblemished physically," blindness only excludeda man from ascending the throne in Wadai; if acquired later, it did not makea man unfit to rule according to the law.^{30(vol 4:p 223)} However, such affliction might lead to a deteriorationin the ability to govern, as demonstrated by Burkomanda, a ruler in Bagirmi:"During the last five years of his life and his reign, his vicious characterwas made still worse by the blindness which set in following a serious eyedisease."^{30(vol 3:p 417)} Likewise,King Hasin of Darfur was blind, apparently from glaucoma, for the last yearsof his reign. During this time, "he became . . . weaker and weaker in directingthe domestic administration of the country."^{30(vol 4:p 315)}

In the travel accounts of Livingstone, Kirk, and Nachtigal, the ophthalmologicalconsequences of exposure to tropical climates and environments are documentedincidentally rather than systematically, and the details given are often infuriatinglybrief. This is perhaps unsurprising because the main object of these journeyswas travel and exploration. Longitudinal clinical observations were not compatiblewith a peripatetic lifestyle. Moreover, the authors had a clear agenda; Livingstone,for instance, was keen to encourage migration to and commerce with Africaand may have underemphasized, wittingly or not, the hazards of disease.

Accepting the difficulty of extrapolating from 19th-century diseasecategories to our own, it seems clear that "ophthalmia," presumably viraland bacterial eye infection, was common—particularly in the desert environment.A correlate of this, also suggested by a comparison of the texts, is thatblindness was more commonly observed in the Saharan environment as opposedto southern Africa. A modern estimate is that the prevalence of blindnessin sub-Saharan countries is around 1.2% as a result of cataracts, glaucoma,trachoma, and onchocerciasis.³³ Smallpox has,of course, been eradicated since these travelers made their journeys.³⁴

These narratives "expose the relentless empiricism of the early tropicaldoctor"^{35(p 32)} and thus are farfrom ideal sources.²⁹ For these reasons, onecould not claim Livingstone, Kirk, or Nachtigal as "pioneers of tropical ophthalmology,"a sobriquet that has perhaps more fittingly been bestowed elsewhere.³⁶ Livingstone and Kirk had received no special trainingin eye diseases, which was probably typical of English medical training atthis time, an age when an interested generalist might still make useful observationson the subject.^{37(pp 217,218)} Ophthalmologywas a much more advanced discipline in Germany, where the ophthalmoscope developedby Hermann von Helmholtz had been available since the early 1850s.³⁸ However, it is unknown whether Nachtigal had anyspecific ophthalmological training.³¹ "Tropicalophthalmology" as a distinct discipline was not established at this time,not for almost another century until the foundation in 1953 of the Institutd'Ophtalmologie Tropicale de l'Afrique in Bamako, Mali.³⁹ Nonetheless,in the absence of significant indigenous records, these travel accounts provideinteresting insights into ophthalmological problems and their treatments.

Corresponding author and reprints: A. J. Larner, MD, MRCP(UK), DHMSA,Walton Centre for Neurology and Neurosurgery, Lower Lane, Fazakerley Liverpool,L9 7LJ, UK (e-mail: a.larner@thewaltoncentre.nhs.uk).

Submitted for publication March 25, 2003; final revision received July8, 2003; accepted August 13, 2003.

I thank Humphrey Fisher, DPhil, for his comments on this manuscript.