Daily Archives: March 4, 2016
iPhoneOgraphy – 04 Mar 2016 (Day 64/366)
Glasses, also known as eyeglasses or spectacles, are devices consisting of lenses mounted in a frame that holds them in front of a person’s eyes. Glasses are typically used for vision correction. Safety glasses provide eye protection against flying debris or against visible and near-visible light or radiation. Sunglasses allow better vision in bright daylight, and may protect one’s eyes against damage from high levels of ultraviolet light. Specialized glasses may be used for viewing specific visual information (such as stereoscopy). Sometimes glasses are worn simply for aesthetic or fashion purposes. The number of Americans who are nearsighted has doubled since the 1970s and almost 3/4 of the US population wears glasses. People are more likely to need glasses the older they get with 93% of people between the age of 65-75 wearing corrective lenses.
The use of a convez lens to form an enlarged/magnified image is discussed in Alhazen’s Book of optics (1021). Its translation into Latin from Arabic in the 12th century was instrumental to the invention of eyeglasses in 13th century Italy.
Englishman Robert Grosseteste’s treatise De iride(“On the Rainbow”), written between 1220 and 1235, mentions using optics to “read the smallest letters at incredible distances”. A few years later in 1262, Roger Bacon is also known to have written on the magnifying properties of lenses.
Sunglasses, in the form of flat panes of smoky quartz, were used in China during the 12th century. Similarly, the Inuit have used snow goggles for eye protection. While they did not offer any corrective benefits they did improve visual acuity via the pinhole effect.
The first eyeglasses were made in Italy in about 1286, but it is not clear who the inventor was. In a sermon delivered on February 23, 1306, the Dominican friar Giordano da Pisa (ca. 1255–1311) wrote “It is not yet twenty years since there was found the art of making eyeglasses, which make for good vision… And it is so short a time that this new art, never before extant, was discovered. … I saw the one who first discovered and practiced it, and I talked to him.” Giordano’s colleague Friar Alessandro Della Spina of Pisa (d. 1313) was soon making eyeglasses. The Ancient Chronicle of the Dominican Monastery of St. Catherine in Pisarecords: “Eyeglasses, having first been made by someone else, who was unwilling to share them, he [Spina] made them and shared them with everyone with a cheerful and willing heart.” By 1301, there were guild regulations in Venice governing the sale of eyeglasses.
The earliest pictorial evidence for the use of eyeglasses is Tommaso da Modena’s 1352 portrait of the cardinal Hugh de Provence reading in a scriptorium. Another early example would be a depiction of eyeglasses found north of the Alps in an altarpiece of the church of Bad Wildungen, Germany, in 1403.
These early glasses had convex lenses that could correct both hyperopia (farsightedness), and the presbyopia that commonly develops as a symptom of aging. It was not until 1604 that Johannes Kepler published the first correct explanation as to why convex and concave lenses could correct presbyopia and myopia.
Early frames for glasses consisted of two magnifying glasses riveted together by the handles so that they could grip the nose. These are referred to as “rivet spectacles”. The earliest surviving examples were found under the floorboards at Kloster Wienhausen, a convent near Celle in Germany; they have been dated to circa 1400.
In 1907 Professor Berthold Laufer, a German-American anthropologist, stated in his history of glasses that “the opinion that spectacles originated in India is of the greatest probability and that spectacles must have been known in India earlier than in Europe”. However, Joseph Needham showed that the mention of glasses in the manuscript Laufer used to justify the prior invention of them in Asia did not exist in older versions of that manuscript, and the reference to them in later versions was added during the Ming dynasty.
Although there have been claims that Salvino degli Armati of Florence invented eyeglasses, these claims have been exposed as hoaxes. Furthermore, although there have been claims that Marco Polo encountered eyeglasses during his travels in China in the 13th century, no such statement appears in his accounts. Indeed, the earliest mentions of eyeglasses in China occur in the 15th century and those Chinese sources state that eyeglasses were imported.
The American scientist Benjamin Franklin, who suffered from both myopia and presbyopia, invented bifocals. Serious historians have from time to time produced evidence to suggest that others may have preceded him in the invention; however, a correspondence between George Whatley and John Fenno, editor of The Gazette of the United States, suggested that Franklin had indeed invented bifocals, and perhaps 50 years earlier than had been originally thought.
The first lenses for correcting astigmatism were designed by the British astronomer George Airy in 1825.
Over time, the construction of frames for glasses also evolved. Early eyepieces were designed to be either held in place by hand or by exerting pressure on the nose (pince-nez). Girolamo Savonarola suggested that eyepieces could be held in place by a ribbon passed over the wearer’s head, this in turn secured by the weight of a hat. The modern style of glasses, held by temples passing over the ears, was developed some time before 1727, possibly by the British optician Edward Scarlett. These designs were not immediately successful, however, and various styles with attached handles such as “scissors-glasses” and lorgnettes were also fashionable from the second half of the 18th century and into the early 19th century.
Shot & Edited using iPhone 6+