Antony van Leeuwenhoek's microscopes and other scientific instruments: new information from the Delft archives.

This paper discusses the scientific instruments made and used by the microscopist Antony van Leeuwenhoek (1632-1723). The immediate cause of our study was the discovery of an overlooked document from the Delft archive: an inventory of the possessions that were left in 1745 after the death of Leeuwenhoek's daughter Maria. This list sums up which tools and scientific instruments Leeuwenhoek possessed at the end of his life, including his famous microscopes. This information, combined with the results of earlier historical research, gives us new insights about the way Leeuwenhoek began his lens grinding and how eventually he made his best lenses. It also teaches us more about Leeuwenhoek's work as a surveyor and a wine gauger. A further investigation of the 1747 sale of Leeuwenhoek's 531 single lens microscopes has not only led us to the identification of nearly all buyers, but also has provided us with some explanation about why only a dozen of this large number of microscopes has survived.

[Who saw them the first?]. / ¿Quién las vio primero?

From the theory of Girolamo Fracastoro in 1530, suggesting the participation of invisible seeds in the contagion of some diseases, to the universal genius Athanasius Kircher, who saw little worms in the blood of patients suffering from plague in 1659 and the final discovery of Anthony Van Leeuwenhoek in 1674, the existence of bacteria was surely in the mind of a few investigators. Kirchner, who seems to be the winner of this race, did not give any special meaning to his observations. Leeuwenhoek, instead, was deeply concerned about the importance of his discovery in the field of biology, but was unable to establish a link between these animalcula and human epidemic diseases.

From Reading Stones, Glasses and Contact Lenses to Intraocular Lenses & Ophthalmic Lasers--A Short Overview over the History of Visual Aids.

Alhazen, ibn al-Haytham, (965 Basra - c. 1040 in Cairo) was a Muslim polymath who made significant contributions to the principles of optics, being the first to recognize the optical effect by transparent objects in the 11th century. His insights led to a fundamental revolution, enabling older presbyopic persons to read again. Today many more options are available to help visually impaired people correct their sight defects. This article will give an historical overview of the sight aids which are available today and will describe the very first beginnings of the development of the "reading stone" or "glasses". Further, it will also give a chronological overview of more modern techniques, e.g., intraocular lenses, contact lenses and the options of refractive surgery.

[Greatness and tribulations of Zeiss and Leitz, two famous German optic companies - I. Zeiss]. / Grandeur et vicissitudes de deux grandes entreprises d'optique allemandes - I. La firme Zeiss.

In a series of three articles, a parallel is drawn between the histories of the two most famous German optic companies, Zeiss and Leitz. Born in the middle of the 19th century, Zeiss went through National Socialism, World War II, partition and reunification of Germany. Archive documents abound, but a careful analysis is necessary to understand or guess the part played by the main actors, as Ernst Abbe, brilliant German physicist, or Küppenbender who eclipsed Emanuel Goldberg, a pioneer in information storage and retrieval. The reunification of Germany provided the opportunity for the reuniting of the eastern and western Carl Zeiss enterprises, creating a macro-economic shock, with radical change for the Carl Zeiss Jena company. Today, Carl Zeiss AG is a global leader in the optical and optoelectronic industry.

[The production of optical glass in France and the experiences of Ruggiero Boscovich for the production of lead glass (Part One)]. / La produzione di vetro ottico in Francia e le esperienze di Ruggiero Boscovich per la produzione di vetro al piombo (Parte Prima).

The experiences that in 1758 led John Dollond to create the first achromatic telescope highlighted the serious difficulties related to the production of lenses with a correction for chromatic aberration. These difficulties were due to the lack of suitable tools for measuring the refraction index and for verifying the curvatures of the lenses of such optical instruments. To this was added what was perhaps the greatest difficulty: i.e., that of acquiring the kinds of glass, the so-called "common" (crown) glass and "lead" (flint) glass, of which the lenses had to be made. If the theoretical works of Alexis Clairaut, of Samuel Klingenstierna, and of Ruggiero Boscovich furnished the theoretical basis for producing such lenses, and subsequently--after Boscovich's discovery of the role of the eyepieces--for creating also achromatic eyepieces, the greatest challenge from the practical point of view was that of the availability of the flint glass. In this first part of the article there is then a study of the numerous attempts and directions pursued by Clairaut and his valid collaborators--Anthéaulme, George father and son, Charles François de l'Etang, and Claude Siméon Passemant--in order to find common glass and lead glass, and to produce the first achromatic lenses and binoculars in France. An analysis follows of the experiences conducted by Boscovich, first in Vienna, and then in Milan and Venice-Murano, addressed to the production of flint glass.

Johannes Amos Comenius (1592-1670) and his depiction of lenses and spectacles in the first children's picture book.

Johannes Amos Comenius (1592-1670) was a Moravian clergyman, teacher, and author. He is recognized as introducing several concepts of modern education. He advanced the views that education should be appropriate to age and development levels and that teaching should make use of everyday sensory experience. One of his many books, Orbis Pictus, followed those concepts. Orbis Pictus, first published in 1657, is hailed as the first children's picture book. Among the many commonplace objects he included in the book were a mirror, spectacles, a telescope, a magnifying lens, and a burning glass.

Desarrollo de la óptica oftálmica y uso de anteojos en la ciudad de México durante los siglos XVI-XVIII / Development of ophtalmologic optics and use of glasses in Mexico city during the XVI-XVIII centuries

El trabajo se propone esclarecer el desarrollo de la producción de lentes oftálmicas y del uso de anteojos en México durante la época colonial.(AU)

Leonardo da Vinci, visual perspective and the crystalline sphere (lens): if only Leonardo had had a freezer.

This study confirms Leonardo's claim to have experimented on the bovine eye to determine the internal anatomy of the eye. The experiment, as described by Leonardo, was repeated in our laboratory. The study further discusses Leonardo's primary interest in the study of the eye (especially the lens), to determine how the image of an object which enters the eye in an inverted form is righted. The study shows the evolution of Leonardo's understanding of the anatomy and the physiology of vision. Initially, in keeping with his reading of the literature, the lens was placed in the centre but he made it globular. Later he promulgated two theories, reflection from the uvea and refraction within the lens to explain reversal of the image in the eye. Subsequently he rejected the first theory and, putting credence in the second theory, experimented (1509) to show that the lens is globular and is centrally placed. The fact that the present knowledge about the lens is at variance from his findings is not because he did not carry out the experiment, as suggested by some modern authors, but because of the limitation of the techniques available to him at the time.

[Greek medicine in ancient times and its ophthalmological aspects]. / Medycyna grecka w czasach antycznych i jej aspekty okulistyczne.

The article presents the state of medical knowledge in ancient Greece. Sacred medicine related to the cult of Asclepius and the origin of secular medicine is described. Ophthalmological aspects concerning the anatomy of the eye, diagnosis and treatment of ocular diseases are emphasized.

Duplication of unique optical effects of ancient Egyptian lenses from the IV/V Dynasties: lenses fabricated ca 2620-2400 BC or roughly 4600 years ago.

Ancient (in fact, first known) lenses (ca. 4600 years ago) mainly from the IVth and Vth Dynasties of Egypt had truly remarkable and unique optical properties. These were parts of equally fascinating eye structures. These structures were fabricated as separate assemblies for insertion into funerary statues during certain brief windows of time (roughly from 2620-2400 BC, and 1750-1700 BC). These "eyes" appear to follow the observer as he/she rotated in any direction about these statues. In this paper, by simple means, we have recreated the optical properties of these unique lenses in the laboratory in order to help understand their special properties.

[Progressive lenses, history and comfort factors]. / Verres progressifs, historique et facteurs de confort.

Since some fifteen years, progressive glasses tend to replace gradually the bifocal ones as first choice of the correction of presbyopia. This tendency varies however according to continents and countries. The idea of the progressive glass returns mainly to a French (Maitenaz) working in 1956 for the firm Essilor. At that time, large reticences had been emitted by the other firms manufacturing glasses, that do not suspect the success that would have later this kind of correction once imperfections of the infancy will have been solved. Progressive glasses have been improved by taking account of remarks of wearers and by privileging the comfort in the current life, ending to glasses well supported by most of the presbyopes.