Who invented eyeglasses?
Eyeglass is also called Glasses, or Spectacles, lenses set in frames for wearing in front of the eyes to aid vision or to correct such defects of vision as myopia, hyperopia, and astigmatism. Eyeglasses, lenses or prisms worn in front of the eyes to compensate for various defects of vision. The most common form of eyeglasses consists of a pair of plastic lenses in a metal or plastic frame fitted to the bridge of the nose. The frame is held in place by spring pressure on the nose or by temples, or arms, that grip the head or hook around the ears. Spectacles with lenses made of a hard plastic are commonly used for reasons of increased safety and light weight. Other forms of eyeglasses include those held in place by pressure on the nose, usually called pince-nez (French, “pinch nose”). Single lenses used to correct the sight of one eye, held in place by wedging in the orbit of the eye, are known as monocles. Glasses with a handle rather than temples, occasionally employed for reading, are called lorgnettes.
Around 1000AD, the first vision aid was invented (inventor unknown) called a reading stone, which was a glass sphere that was laid on top of the material to be read that to magnified the letters. In 1268 the English philosopher Roger Bacon recorded the earliest statement about the optical use of lenses. Possibly as early as the 10th century, however, the Chinese had made use of magnifying glasses placed in frames. Eyeglasses were first used in Europe in Italy, and some portraits dating from the Middle Ages depict persons wearing eyeglasses. With the invention of the printing press in the 15th century, the demand for eyeglasses increased and by 1629 was large enough for a charter to be granted to a guild of spectacle makers in England. The first bifocal glasses were made for Benjamin Franklin at his suggestion about 1760. In 1784 Benjamin Franklin invented bifocals, dividing his lenses for distant and near vision, the split parts being held together by the frame. Cemented bifocals were invented in 1884, and the fused and one-piece types followed in 1908 and 1910, respectively. Trifocals and new designs in bifocals were later introduced, including the Franklin bifocal revived in one-piece form. In early times the only eyeglasses having spherical lenses were manufactured to correct nearsightedness and farsightedness. Not until the end of the 19th century did the cylindrical lens for the correction of astigmatism come into common use.
Today, the doctor of optometry (O.D.), called an optometrist, examines the eyes for defects of vision and prescribes corrective eyeglasses or contact lenses. In Europe, this specialist is known as an optician or ophthalmic optician, but in the United States the optician is concerned with making lenses and spectacles. In contrast, the oculist, or ophthalmologist (M.D.), specializes in medical or surgical treatment of eye diseases or abnormalities of the eye.
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