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Renaissance Vision from Spectacles to Telescopes

2008; Lippincott Williams & Wilkins; Volume: 85; Issue: 7 Linguagem: Inglês

10.1097/opx.0b013e31817dd39b

1538-9235

David A. Goss,

History and Developments in Astronomy

Renaissance Vision from Spectacles to Telescopes Vincent Ilardi. Philadelphia: American Philosophical Society; 2007. $85.00.FigureThis well- researched book covers a broad range of topics related to the history of spectacles, from their invention to their economics, production, and distribution over the following three centuries to the development of the telescope. The author, Vincent Ilardi, is Professor Emeritus of History at the University of Massachusetts, Amherst. His particular area of expertise is history of the fifteenth century, especially diplomatic history. Ilardi's interest in the history of spectacles resulted from his discovery of two large orders of eyeglasses from dukes of Milan that were placed with spectacle makers in Florence between 1462 and 1466. He subsequently found evidence of a flourishing spectacle production and exportation industry in fifteenth century Florence. He states that "by the end of the fifteenth century, Florence and similar urban areas were awash with eyeglasses in varying degrees" (pages 178–179). The 1462 order of spectacles discovered by Ilardi was placed with Florentine spectacle makers by Duke Francesco Sforza of Milan through his ambassador in Florence. The order specified that there should be a dozen pairs of eyeglasses "apt and suitable for distant vision, that is for the young," a dozen "suitable for near vision, that is for the elderly," and another dozen for more "common vision" (page 82). It is likely that the spectacles for common vision contained plus lenses for beginning presbyopes. The distant vision spectacles for the young probably contained minus lenses. This appears to be the first documentation of the use of minus lenses. The earliest spectacles following their invention in about 1286 were ones with plus lenses for presbyopia. It is thought that the large numbers of pectacles in these orders was because they were to be presented as gifts. Another order for spectacles from Milan to Florence was placed in 1466 by Sforza's son and successor, Galeazzo Maria. This order specified certain numbers of spectacles for ages in 5-year intervals from 30 to 70 years, along with eyeglasses for medium vision and distant vision for the young. Thus there were by this time, several powers of plus lenses used for presbyopia and at least two powers of minus lenses for myopia. Ilardi also uncovered a 1488 diary of a Florentine ambassador to Egypt and the Holy Land in which was mentioned the age levels of the spectacles that the ambassador had promised to friars in Jerusalem. Thus it is evident that by the mid-fifteenth century it was known that presbyopia advanced, requiring increasing plus lens powers. The author notes that optical scientists did not take up the question of the optics of spectacle lenses until spectacle making was centuries old. The optical writings of Peckham, Bacon, and Witelo in the thirteenth century dealt with natural philosophy (basic science) rather than applied science. It was not until Francesco Maurolico in the mid-sixteenth century and Johannes Kepler in the early seventeenth century that the optics of spectacle lenses were seriously examined. Medical prejudice against spectacles started early. In a small book published in 1361 as part of a medical and surgical manual and entitled Prescriptions for the Eyes, Maestro Piero Ubertini da Brescia recommended herbal pills rather than eyeglasses for clear vision. French surgeon and professor of medicine Guy de Chauliac (c. 1300–1368) mentioned spectacles only as a last resort by in his 1363 book Chirurgia Magna if treatments such as potions with fennel seeds did not relieve vision problems. Advice by medical authorities to avoid the use of eyeglasses can also be found in the book Ophthalmodouleia, a treatise on eye diseases and ocular surgery by George Bartisch (1535–1606). Among the remedies Bartisch recommended to avoid weak vision were various potions, purges, pills, and eye powders. Early spectacles that have been discovered often have the lenses missing or in such poor shape that power determinations are difficult. One example from the early or mid-sixteenth century found in an Italian archives had biconvex lenses with powers of +1.50 D on each surface for a lens power of about +3 D. Another pair of Italian spectacles from the late sixteenth or early seventeenth century contained plus lenses of about +3 D. Ilardi also cites a finding of 300 pairs of spectacles in a shipwreck off the coast of Croatia. Those spectacles are thought to have been of German origin and date to the late sixteenth century. The powers of ones preserved well enough to make a power determination were +3 to +3.5 D. Ilardi discusses various aspects of the spectacle making trade and the construction of spectacles. For example, he mentions a 1585 encyclopedia of occupations by Tommaso Garzoni which included the occupation of spectacle maker. Garzoni described the grinding of convex and concave lenses for various ages and a measuring scale for the power of lenses. Ilardi also elaborates on the contents of the 1623 book by Daza de Valdes of Spain, generally recognized as the first book that could be considered a book on optometric procedure and analysis. Early spectacle frames were made from bone, leather, horn, wood, and other materials and had a bridge that could rest on the nose, but no temples. The bone frames were typically made with circular rims with handles extending from the rims and the handles connected with a rivet. The lenses could be held with one over each eye or they could be rotated at the rivet so that the lenses were superimposed for looking at finer objects with one eye. When not in use, the spectacles could be folded up and placed in a bag suspended by a string from the belt. It is thought that the first use of a "temple" to help hold spectacles in place was the use of cords or strings wrapped around the ears in late sixteenth century Spain. The first five chapters of the book contain a great amount of detail on the history of spectacles, particularly in Italy. The sixth and final chapter discusses the development of telescopes and lens making and touches on the early history of the study of retinal imagery. Contributions by Della Porta, Manzini, Bacon, Maurolico, da Vinci, Kepler, and others are discussed. The book contains three appendices. The first appendix is a list of 48 artisans known to have worked as spectacle makers in Florence between 1413 and 1562, and the second discusses four friars in Florence who were also spectacle makers. The largest appendix is the third one. It documents examples of spectacles in art, listing paintings that contain depictions of early spectacles. The third appendix includes 77 figures, mostly color reproductions of paintings, but also a few photographs of fifteenth to seventeenth century spectacles. Anyone wishing to learn extensive details about the history of eyeglasses should consult this book. A disappointment I had with this book did not concern the quality of Ilardi's work at all, but rather what one of his statements in the preface indicated about the current interests of optometrists and optometric educators. He mentioned his original 1976 article on the orders of spectacles by the dukes of Milan in the fifteenth century, and that he was encouraged to write this book by "the many requests for offprints of the article by ophthalmologists, opticians, and medical schools. t.t." (page ix). The conspicuous absence of the mention of optometrists and optometry schools from that statement is another indication that we should do a better job of getting involved in the study of our profession's history (see Goss DA. The status of the study of optometry history. Hindsight: J Optom Hist 2007;38:3–7). This is an exceptionally well-researched book which offers new insights into the history of spectacles and spectacle makers. It provides an example of the excellent scholarship that can be done in the history of optometry. The book is attractively produced and contains a comprehensive 28-page bibliography. David A. Goss School of Optometry Indiana University Bloomington, Indiana