While it’s uncertain who the inventor was, it is quite clear that spectacles quickly took hold into common use in that city, and use of them spread outward to the rest of the known world in just a few years. The Invention of Spectacles: The modern reinvention of spectacles occurred around 1280-1285 in Florence, Italy. Strangely, even though this must have worked quite well, and many people must have read this passage, there is no other evidence of spectacle use for over twelve centuries. The Emperor Nero used to watch in an Emerald the gladatorial combats.” This quote appears to be the first description of using a monacle for correcting short-sighted vision. Pliny the Elder wrote the following in 23-79 A.D.: “Emeralds are usually concave so that they may concentrate the visual rays. There is one very early description of an isolated use of spectacles. However, studies of early Chinese spectacles show that often the lenses were planar, without corrective abilities, and people may have actually used these colored glasses for cosmetic purposes rather than for astigmatism. Early Evidence of Spectacle Use: It has been said that spectacles were in use in China well before they were known in the West. It wasn’t until the invention of spectacles that optics came into common use. While the above exerpts give a glimpse at optical knowledge in the past, it’s important to realize that this knowledge was likely confined to the learned scientists and philosophers. If the letters of a book, or any minute object, be viewed through a lesser segment of a sphere of glass or crystal, whose plane is laid upon them, they will appear far better and larger. 1267 AD Bacon Wrote definite descriptions of simple magnification in his Perspectiva of 1267: “Great things can be performed by refracted vision. He wrote the following: “Letters, however small and indistinct, are seen enlarged and more clearly through a globe of glass filled with water.” 962-1038 AD: Arabian Scholar Alhazen: Wrote the first major optical work Opticae Thesaurus discussing not only optical principles, but described the anatomy of the eye, and how the lens of the eye focuses an image on the retina. 1st Century AD: Seneca: Described actual magnification by a globe of water. He then very accurately calculated the refraction constant of water. 2nd Century BC: Claudius Ptolemy:Described a stick appearing to bend in a pool of water, and accurately recorded the angles to within ½ degree for this relationship. Ancient Writings of Optics Several ancient manuscripts give us datable evidence of the state of refraction and optics throughout the ages. It’s now thought that lenses were not used nearly so long ago. It is now generally agreed that this stone was actually just an ornament which fell away from it’s mounting. Secondly, cloudy striae within the stone, which add an aesthetic quality, make it a poor magnifier. In the last century, however, studies of this object have shown that the curved surface is actually faceted, and not rounded, as one would have done to make a lens. This was long thought to be the first example of a plano-convex lens. The Lanyard Lens: The above is the famous “Lanyard Lens” discovered at Nimrod by Lanyard, and datable to 721-705 BC. This chapter should give some insighs on how optical theory developed making microscopy possible. Early History of the Lens: The first use of a lens is a bit of a mystery, but it’s now believed that use of lenses is more modern than previously thought. I great ly encourage anyone with corrections, disagreements, or suggestions to send me email About the Images in this Document: The images used in this document are derived from many sources, such as the original historic documents, the National Library of Medicine’s History of Medicine While I am working to replace copyrighted pictures, I urge anyone who wishes to use these images to research the copyright status before using them in non-private work. A number of good books exist on the topic, and several are listed under the Scientific Books section of the “Scientific and Medical Antique Collecting System” which I also encourage you to visit. I encourage you to visit this page as a complement covering some later developments. which covers more recent (20th century) improvements. Another “History of Microscopy” is maintained by Chris Jefferies in the U.K. This paper covers the early history of the microscope, starting with use of a simple lens in ancient times, to the first compound microscope circa 1590, up to the microscopes of the 19th century. Introduction: The microscope has become one of the most recognizable symbols of science. Ĭhapter 6: The Microscopes of the 19th Century Chapter 3: Microscopes of the 17th CenturyĬhapter 4: Mechanical Improvements of the 18th CenturyĬhapter 5: The Achromatic Lens Dispute.
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