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Man with glasses. A woman with glasses. Glasses, also known as eyeglasses or spectacles, are vision eyewear with clear or tinted lenses mounted in a frame that holds them in front of a person's eyes, typically utilizing a bridge over the nose and hinged arms, known as temples or temple pieces, that rest over the ears for support.
Often used by monks to assist in illuminating manuscripts, these were primitive plano-convex lenses, initially made by cutting a glass sphere in half. As the stones were experimented with, it was slowly understood that shallower lenses magnified more effectively. Around 1286, possibly in Pisa, Italy, the first pair of eyeglasses was made ...
A very important advance in glass manufacture was the technique of adding lead oxide to the molten glass; this improved the appearance of the glass and made it easier to melt using sea-coal as a furnace fuel. This technique also increased the "working period" of the glass, making it easier to manipulate.
The first incarnations of glasses were made with the aim of providing aid to reading. [ 8 ] Though innovations in pre-modern eyewear technology occurred in both Imperial China and the Inuit territories, which both invented early forms of sunglasses and goggles, [ 9 ] Venice and Northern Italy have historically been the place of consolidation ...
In 1913, Crookes lenses [17] were introduced, [18] made from glass containing cerium, which completely blocked ultraviolet light. [19] [20] In the early 1920s, the use of sunglasses started to become more widespread, especially among movie stars. Inexpensive mass-produced sunglasses made from celluloid were first produced by Sam Foster in 1929.
To combat fake solar eclipse glasses, the American Paper Optics team created the Core Four elements of eclipse glasses to look out for to ensure your safety during the solar event.
In the 1790s, the O'Hara and Craig glass works was the first glass works in Pittsburgh, and this works was another early user of coal as a fuel for its furnaces. [67] By 1800, it is thought that roughly ten glass works were operating in the United States. [68] Challenges for American glass works revolved around labor, raw materials, and imports.
Kicking back with a glass of wine is certainly one way to relax, but how about watching how your glass got made in the first place? This mind-blowing video shows how wine glasses are made in a factory