Legend, scholastic disputes, travellers' tales, local patriotism and downright fabrications have all encumbered the quest for knowledge on the early history of glasses. Rock glass must have been known in early times, but even manufactured glass has a considerable antiquity. A wall painting at Beni Hasan, which accurately depicts the process of glass blowing, is attributed to the period of the XI th dynasty, though there is no evidence of any manufacture of glass in Egypt till the much later XVIIIth dynasty. References to glass and its manufacture also abound in the Bible. Pliny assigned the origin of glass manufacture to the accidental discovery by Phoenician merchants of a glass-like substance under their cooking pots, which had been supported by blocks of nitron. It is not unlikely that some such accident - the fusion by heat of impure sodium carbonate with sand, started off the quest for a less brittle and more transparent substance than was produced in this manner. The manufacture of glass for the production of vases, mirrors and gems of all sorts had developed into an advanced industry long before Roman times.Legend has it that St. Jerome (c. 340-420 AD) invented glasses. On more definite evidence the use of glasses in remoter antiquity has been considered. Pliny records the 'Nero princeps gladiatorium pugnas spectabat zmaragdo" and this vague reference to Nero watching gladiatorial contests with an emerald has been read to mean that he used glasses. The emerald may well have had other uses, as a gem, as the sporting of the green colours of the Emperor, as an amulet - for emeralds had a reputation for strengthening the eye - and so on. Presumably Nero was short-sighted, but what is known about his sight rather suggests the photophobia of the albino, for which indeed he may have used green glass as a protective. It is certainly a fact that myopia and the weak sight of old people was well known tot he Romans, but nowhere at that period and for many centuries subsequently is there nay reference to glasses. Indeed myopia was regarded as a permanent defec,. as is shown by the fact that Roman lawyers considered myopia a vicium perpetuum, diminishing the market value of a slave; and as for presbyopia, the only way Roman patricians knew of overcoming it was by getting a slave to read to them.
Travellers' tales have made China the original centre of glasses. The earliest evidence concerning glasses in China is, however, of considerably later period that the time they made their appearance in Europe. The Chinese probably learnt about glasses indirectly from Europe through the intermediary of the inhabitants of Malacca.
Magnifying glasses of a sort were known and may have been used in antiquity. The effect of a glass bowl filled with water in showing up details was recognized, as can be seen from a reference in Seneca. Furthermore, Pliny relates that such bowls were used by physicians for burning. The glass bowl was obviously used as a condensing lens, though it was a wonder to the Romans that cold water should be able to burn. Dimly the biconvex lens was already known.
Alhazen had carried the theory of vision to a sufficiently advanced level almost to have been able to introduce the use of lens. But it was left for subsequent centuries actually to achieve it. The first recognition of these possibilities seems to have come with Roger Bacon, as seen from a passage not devoid of gross errors. He discusses the use of segments of spheres and shows that letters and small objects on which they are placed appear magnified. "For this reason such an instrument is useful to old persons and to those with weak sight, for they can see any letter, however small, if magnified enough."
The observation that segments of spheres magnify was not original with Bacon; what constitutes an advance is the clear recognition of their use for old people and those with weak sight. If it was not eye-glasses that Bacon had in mind, he advocated the loupe or magnifying glass, the forerunner of spectacles.
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References to glasses begin to crowd at the beginning of the 14th century; they, therefore, must have attracted considerable attention towards to the end oft the 13th century. The first medical reference is by Bernard Gordon, Professor of Montpellier (1305). He recommends a collyrium of such potency "that it will enable those whose sight is weak from old age to read without glasses." Guy de Chauliac (1353) likewise recommends collyria, but adds that when they do not help, recourse should be had to glasses. Incidentally, collyria were time-honoured means for strengthening the sight. Ali ben Isa has laid down explicitly that they who do not see in the near, "a condition which mainly affects old people" should use styptic medicines; whilst those who see well near by but not in the distance, require medicines which give moist nutrition and bring the moist principle to the eye.Attempts to trace the invention of glasses to a particular person have had little success. Fraciscus Redi, a distinguished and learned Professor of Medicine in Pisa, in letters to a friend in 1676, writes that he has a manuscript dated 1299, in the preface of which a reference is made to the recently invented glasses; " I find myself so oppressed by the years that I no longer have the strength to read or write without the glasses known as spectacles, lately invented for the comfort of the old souls who have become weak-sighted." Redi further quotes from a sermon (1305) by Fra Giordano da Rivalto: " It is not yet twenty years that the art of making glasses was invented; this enables good sight and is one of the best as well as the most useful of arts that the world possess." Fra Giordano resided together with Fra Alessandro da Spina in the monastery of S. Catherina at Pisa, and Redi extracted from the manuscript chronicle of the monastery two references to Spina. One is an obituary notice, Spina having died in 1313, two years after Fra Giordano: "Brother Alexander da Spina, a modest and good man, had the capacity to make things he had seen or of which he had heard. He made glasses and freely taught the art to others. Glasses had previously been made by someone else who, however, would not say anything about them." Another reference in that chronicle speaks in the same tone and to the same effect, emphasizing that in contrast tot he secretiveness of the original inventor, da Spina freely communicated the secret of the art he had copied.
Thus while Alexander da Spina, a Dominican monk, is generally accepted as the re-inventor of glasses, the original inventor is lost to history. It is in fact doubtful whether there was such as one; it is just as likely that the value of glasses was found empirically towards the end of the 13th century owing to the accidental use of the somewhat plano-convex glass of some forms of window-plane. Bacon, who had the requisite theoretical knowledge, did not apparently get as far as glasses, whilst the claims for Salvino Armato of Florence are largely based on the excessive zeal of a Florentine historian, Domenico Manni.
Manni relates that a Florentine antiquary saw a tomb-stone inscription in the now demolished church of St. Maria Maggiore at Florence which read:: "Here rests Salvino d'Armato of the Armati of Florence, the inventor of spectacles. God pardons his sins. A.D. 1317." Manni held that Armato was the secretive inventor spoken of in the references to da Spina, and this flimsy view has somehow gained widespread acceptance.
What looked like more conclusive evidence was published in 1845 by Casemaecker of Ghent. A rather lurid story is told of Roger Bacon - incidentally translated into a Belgian - fleeing before Papal wrath and passing on his invention of spectacles to a friend, from whom it was that da Spina heard of glasses. Bacon himself was most anxious not to attract further attention from the Church, as he was already in heavy disfavour for his other works. To Hirschberg, this tale, along with its other lurid details, sounded like a bad detective story, and on investigating it he found that though it had been accepted as authentic history it was nothing more than pure invention written by a journalist for its reputed author, an optician.
It was therefore somewhere towards the 13th century that glasses came to be introduced. Glasses began to have a vogue towards the middle oft he 14th century; and painters and sculptors could not resist the temptation to endow biblical figures with these accessories. Glasses were even deemed necessary in the Garden of Eden. Public documents make references to them and wills dispose carefully of spectacles, for they were still a costly item. It was not till the beginning of the 16th century that the concave glass began to be used; Pope Leo X, painted by Raphael between 1517 and 1519, is depicted holding a concave lens, and a number of later references in books abound. But it was not till Kepler (1604) that the whole subject was clearly conceived.
Spectacles were not well received by the oculists. Bartisch scornfully dismisses them; he could not conceive how an eye that does not see well would see better with something in front of it. Even after Kepler, collyria for weak sight prospered. Nevertheless a great deal of practical and useful information was being collected by humber vendors of glasses, and this was well systematized in an utterly unscientific treatise published in Spain in 1623 by Daza de Valdés, "licentiate and notary of the Inquisition in the City of Seville." The use of high convex lenses after cataract operations is clearly indicated, whilst a scale of different strengths of reading glasses for different ages is laid down. For a man between 30 and 40, lenses of 2 degrees were needed; for one aged between 70 and for higher ages lenses of five to six degrees. Women required more than double the strength, for not only do they perform more delicate work, but their eyes are naturally weaker.
Almost down to the middle of the 19th century the fitting of glasses was the prerogative of untrained vendors -- mostly itinerant, who combined this business with the other occupations usual to pedlars. Oculists took but the slightest interest in the matter, at the most recommending a patient to go to a shop and select the most suitable pair obtainable. The range of choice was of course not wide. The stock in trade consisted of glasses after cataract operation, glasses for old sight, glasses for short sight and occasionally glasses for "old sight of young people". Astigmatism was not known till Young demonstrated it in his own eyes in 1801; that a correction was possible was not realized till Airy designed a suitable cylindrical lens in 1827. But even so it was not till after Donders and the subsequent introduction of retinoscopy that the treatment of astigmatism assumed any tangible practical form.
Indeed, almost until Donders glasses met with a remarkable hostility. During the earlier part of the 19th century there was much hostility, largely the result of Beer's attitude to them, for Beer had little more use for them than Bartisch. Weller, in a standard book in 1832, advises against concave lenses if the eye is to be saved from deformation, and is to preserve its ability to become far-sighted after the age of 40. Sichel, another important contemporary writer, sees in concave lenses the cause of old sight, whilst yet another author blames glasses for the development of short sight. Here and there, particularly in England, an isolated voice was raised pleading for the use of glasses. In this connection the charlatan Rowley deserves to be remembered, as also Kitchiner and Lawrence. The trial case was first introduced in 1843, and in the same year Küchler introduced test types for near. Eleven years later Jaeger introduced test types for both near and distance, though it was left to Snellen to put these on a scientific basis. By the use of the ophthalmoscope Jaeger paved the way for the objective determination of refractive errors, in the development of which the names of Bowman (1859) and Cuignet (1875) stand out. But it was largely the work of Donders that made the problems of refraction and the rational use of glasses part of the ophthalmic creed.
The introduction of prisms into ophthalmology also dates from this period. First introduced by Kepler, pioneer work in their clinical application had been carried out by Wells in 1792; yet it was not till Donders in 1847 and especially von Graefe in 1857 showed their value in muscle insufficiency, that any serious attention was given to their possibilities.
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In this later life, Benjamin Franklin developed presbyopia. As he was also myopic, he got tired of constantly having to interchange two paris of glasses. So he decided to figure out a way to make his glasses let him see both near and far. He had two pairs of spectacles cut in half and put half of each lens in a single frame to make a bifocal.
The evolution of the spectacle frame has a history of its own. The oldest spectacles, known to us from a painting by di Modena in 1352, consisted of two lenses in rims, joined centrally. The inconvenience of holding such glasses in position for any length of time led to a modification suggesting sugar-tongs. Metal rims gave way to leather ones; such a pair has been found preserved within a book. An early modification -- incidentally recommended by Savodarola -- was to secure the glasses by a tape tucked under the hat, a method rather reminiscent of the Chinese way of binding the glasses to the head gear. Various forms of lorgnette followed. The original attempts at ear-rails added greatly to the already heavy weight of spectacles. It was only towards the end of the 18th century that passable ear-rails came to be introduced. These were followed by glasses with nose-pieces having a spring, a marked advance on the much earlier nose-riders which were kept in position by the pressure the rims exercised on the nose. Gold, silver, steel, fish-bone, horn, wood and leather have all been used for the making of the spectacle frame.
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Dear Mrs. Mills, I have worn a monocle on and off for the past few years.
I now feel totally comfortable
DPC, Lincs Dear DPC, While the monocle should be worn whenever needed for
seeing clearly (ie, reading,
Mrs. Mills
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