Glasses (also called eyeglasses or spectacles) are frames bearing lenses A lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light, converging or diverging the beam. A simple lens is a lens consisting of a single optical element. A compound lens is an array of simple lenses with a common axis; the use of multiple elements allows more optical aberrations to be corrected worn in front of the eyes Eyes are organs that detect light, and send signals along the optic nerve to the visual and other areas of the brain[citation needed]. Complex optical systems with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system. Image-resolving eyes are present in cnidaria, molluscs,, normally for vision correction A corrective lens is a lens worn in front of the eye, mainly used to treat myopia, hyperopia, astigmatism, and presbyopia. Glasses or "spectacles" are worn on the face a short distance in front of the eye. Contact lenses are worn directly on the surface of the eye. Intraocular lenses are surgically implanted most commonly after cataract, eye protection Eye protection is protective clothing for the eyes, which comes in many types depending upon the threat that is to be reduced. The threats can be particles, light, wind blast, heat, sea spray or some type of ball or puck used in sports, or for protection from UV rays Ultra-violet cured coatings can be applied over ink printed on paper and dried by exposure to UV radiation. UV coatings can be formulated up to 100% solids so that they have no volatile component that contributes to pollution. This high solids level also allows for the coating to be applied in very thin films. UV coatings can be formulated to a.

Modern glasses are typically supported by pads on the bridge of the nose Anatomically, a nose is a protuberance in vertebrates that houses the nostrils, or nares, which admit and expel air for respiration in conjunction with the mouth. Behind the nose is the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passes through the pharynx, shared with the digestive system, and then into the rest of the and by temples placed over the ears The ear is the organ that detects sound. The vertebrate ear shows a common biology from fish to humans, with variations in structure according to order and species. It not only acts as a receiver for sound, but plays a major role in the sense of balance and body position. The ear is part of the auditory system. Historical types include the pince-nez Pince-nez are a style of spectacles, popular in the nineteenth century, which are supported without earpieces, by pinching the bridge of the nose. The name comes from the French language - pincer, to pinch, and nez, nose, monocle A monocle is a type of corrective lens used to correct the vision in only one eye. It consists of a circular lens, generally with a wire ring around the circumference that can be attached to a string. The other end of the string is then connected to the wearer's clothing to avoid losing the monocle. The connoisseur of antiquities Philipp von, lorgnette A lorgnette is a pair of spectacles with a handle, used to hold them in place, rather than fitting over the ears. They were invented by an Englishman named George Adams. The lorgnette was usually used as a piece of jewelry, rather than to enhance vision. Fashionable ladies usually preferred them to spectacles. These were very popular at masquerade, and scissors-glasses The invention of scissors-glasses solved the problem of the single lens , by providing two lenses on a "Y" shaped frame. They usually had a ring in the end of the handle so that they could be worn on a ribbon or gold chain around the neck.

Eyeglass frames are commonly made from metal or plastic. Lenses were originally made from glass Glass generally refers to hard, brittle, transparent material, such as those used for windows, many bottles, or eyewear. Examples of such materials include, but are not limited to, soda-lime glass, borosilicate glass, acrylic glass, sugar glass, isinglass , or aluminium oxynitride. In the technical sense, glass is an inorganic product of fusion, but many are now made from various types of plastic Plastic is the general common term for a wide range of synthetic or semisynthetic organic amorphous solid materials suitable for the manufacture of industrial products. Plastics are typically polymers of high molecular weight, and may contain other substances to improve performance and/or reduce costs, including CR-39 and polycarbonate Polycarbonates are a particular group of thermoplastic polymers. They are easily worked, moulded, and thermoformed; as such, these plastics are very widely used in the modern chemical industry. Their interesting features position them between commodity plastics and engineering plastics. Their plastic identification code is 7. These materials reduce the danger of breakage and weigh less than glass lenses. Some plastics also have more advantageous optical properties than glass, such as better transmission of visible light The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 380 to 750 nm. In terms of frequency, this corresponds to a band in the vicinity of 790–400 and greater absorption of ultraviolet light Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than x-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV. It is so named because the spectrum consists of electromagnetic waves with frequencies higher than those that humans identify as the color violet.[1] Some plastics have a greater index of refraction The refractive index of a medium is a measure of how much the speed of light (or other waves such as sound waves) is reduced inside the medium. For example, typical soda-lime glass has a refractive index of 1.5, which means that in glass, light travels at 1 / 1.5 = 0.67 times the speed of light in a vacuum. Two common properties of glass and other than most types of glass; this is useful in the making of corrective lenses shaped to correct various vision abnormalities The World Health Organization publishes a classification of known diseases and injuries called the International Statistical Classification of Diseases and Related Health Problems or ICD-10. This list uses that classification such as myopia Myopia , also called nearsightedness or shortsightedness, is a refractive defect of the eye in which collimated light produces image focus in front of the retina when accommodation is relaxed, allowing thinner lenses for a given prescription An eyeglass prescription is a written order by an optometrist, ophthalmologist, orthoptist or an optician for eyeglasses. It specifies the refractive power to which the eyeglasses are to be made in order to correct blurred vision due to refractive errors, including myopia, hyperopia, astigmatism, and presbyopia. It is typically determined using a. Newer plastic lenses, called izon, can also correct for the higher order aberrations that naturally occur in the surface of our eye.[citation needed] These lenses create sharper vision for the people who have problems with sight and help with the halos, starbursts, and comet-tails often associated with night time driving glare.[citation needed] Wavefront guided LASIK LASIK or Lasik is a type of refractive surgery for correcting myopia, hyperopia, and astigmatism. LASIK is performed by ophthalmologists using a laser. The procedure is generally preferred to photorefractive keratectomy, PRK, (also called ASA, Advanced Surface Ablation) because it requires less time for the patient's recovery, and the patient surgery also corrects for the higher order aberrations.

Scratch-resistant coatings can be applied to most plastic lenses giving them similar scratch resistance to glass. Hydrophobic Hydrophobic molecules tend to be non-polar and thus prefer other neutral molecules and nonpolar solvents. Hydrophobic molecules in water often cluster together forming micelles. Water on hydrophobic surfaces will exhibit a high contact angle coatings designed to ease cleaning are also available, as are anti-reflective coatings Antireflective or anti-reflection coatings are a type of optical coating applied to the surface of lenses and other optical devices to reduce reflection. This improves the efficiency of the system since less light is lost. In complex systems such as a telescope, the reduction in reflections also improves the contrast of the image by elimination of intended to reduce glare, improve night vision and make the wearer's eyes more visible.[2]

CR-39 lenses are the most common plastic lenses due to their low weight, high scratch resistance, and low transparency for ultra violet and infrared radiation. Polycarbonate and Trivex lenses are the lightest and most shatter-resistant, making them the best for impact protection,[1] yet offer poor optics due to high dispersion, and having a low Abbe number In physics and optics, the Abbe number, also known as the V-number or constringence of a transparent material, is a measure of the material's dispersion in relation to the refractive index. It is named for Ernst Abbe (1840–1905), the German physicist who defined it of 31.

Not all glasses are designed solely for vision correction but are worn for protection, viewing visual information (such as stereoscopy Stereoscopy, stereoscopic imaging or 3-D imaging is any technique capable of recording three-dimensional visual information or creating the illusion of depth in an image. The illusion of depth in a photograph, movie, or other two-dimensional image is created by presenting a slightly different image to each eye. Many 3D displays use this method to) or simply just for aesthetic or fashion values. Safety glasses are a kind of eye protection Eye protection is protective clothing for the eyes, which comes in many types depending upon the threat that is to be reduced. The threats can be particles, light, wind blast, heat, sea spray or some type of ball or puck used in sports against flying debris or against visible and near visible light Light is electromagnetic radiation, particularly radiation of a wavelength that is visible to the human eye , or perhaps 380–750 nm. In physics, the term light sometimes refers to electromagnetic radiation of any wavelength, whether visible or not or radiation In physics, radiation describes any process in which energy emitted by one body travels through a medium or through space, ultimately to be absorbed by another body. Non-physicists often associate the word with ionizing radiation , but it can also refer to electromagnetic radiation (i.e., radio waves, infrared light, visible light, ultraviolet. Sunglasses Sunglasses or sun glasses are forms of protective eyewear that usually enclose or protect the eye area in order to prevent strong light from reaching the eyes. They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist which feature lenses that are coloured, polarized or darkened. In the early 20th century allow better vision in bright daylight, and may protect against damage from high levels of ultraviolet light Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than x-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV. It is so named because the spectrum consists of electromagnetic waves with frequencies higher than those that humans identify as the color violet.

Contents

History of eyeglasses

Precursors

Detail of a portrait of Hugh de Provence, painted by Tomaso da Modena in 1352

The earliest historical reference to magnification Magnification is the process of enlarging something only in appearance, not in physical size. This enlargement is quantified by a calculated number also called magnification. When this number is less than one it refers to a reduction in size, sometimes called minification or de-magnification dates back to ancient Egyptian Ancient Egypt was an ancient civilization of eastern North Africa, concentrated along the lower reaches of the Nile River in what is now the modern state of Egypt. The civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh, and it developed over the next three millennia. Its history hieroglyphs Egyptian hieroglyphs was a formal writing system used by the ancient Egyptians that contained a combination of logographic and alphabetic elements. Egyptians used cursive hieroglyphs for religious literature on papyrus and wood. Less formal variations of the script, called hieratic and demotic, are technically not hieroglyphs in the 8th century BC, which depict "simple glass meniscal lenses A lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light, converging or diverging the beam. A simple lens is a lens consisting of a single optical element. A compound lens is an array of simple lenses with a common axis; the use of multiple elements allows more optical aberrations to be corrected". The earliest written record of magnification dates back to the 1st century AD, when Seneca the Younger Lucius Annaeus Seneca (c. 4 BC – AD 65) was a Roman Stoic philosopher, statesman, dramatist, and in one work humorist, of the Silver Age of Latin literature. He was tutor and later advisor to emperor Nero. He was later executed by that emperor for complicity in the Pisonian conspiracy to assassinate this last of the Julio-Claudian emperors;, a tutor of Emperor Nero Nero Claudius Caesar Augustus Germanicus , born Lucius Domitius Ahenobarbus, also called Nero Claudius Caesar Drusus Germanicus, was the fifth and final Roman emperor of the Julio-Claudian dynasty. Nero was adopted by his great uncle Claudius to become heir to the throne. As Nero Claudius Caesar Augustus Germanicus, he succeeded to the throne on 13, wrote: "Letters, however small and indistinct, are seen enlarged and more clearly through a globe or glass filled with water".[3] Emperor Nero is also said to have watched the gladiatorial games A Gladiator was an armed combatant who entertained audiences in the Roman Republic and Roman Empire in violent confrontations with other gladiators, wild animals, and condemned criminals. Some gladiators were volunteers who risked their legal and social standing and their lives by appearing in the arena. Most were despised as slaves, schooled using an emerald Emeralds are a variety of the mineral beryl (Be3Al26,) colored green by trace amounts of chromium and sometimes vanadium. Beryl has a hardness of 7.5 - 8 on the 10 point Mohs scale of mineral hardness. Most emeralds are highly included, so their brittleness (resistance to breakage) is classified as generally poor. The word "emerald" as a corrective lens.[4]

Corrective lenses were said to be used by Abbas Ibn Firnas Abbas Ibn Firnas , also known as Abbas Qasim Ibn Firnas and العباس بن فرناس (Arabic language), was an Arabic-speaking Berber, born in Izn-Rand Onda, al-Andalus (today's Ronda, Spain), who lived in the Umayyad Caliphate of Córdoba in al-Andalus. He was a polymath, aviator, chemist, engineer, humanitarian, inventor, musician, physician, in the 9th century,[5] who had devised a way to produce very clear glass. These glasses could be shaped and polished into round rocks used for viewing and were known as reading stones A reading stone was an approximately hemispherical transparent object placed on top of text to magnify the letters so that people with presbyopia could read the text more easily. Reading stones were among the earliest common uses of lenses. The earliest evidence of "a magnifying device A magnifying glass is a convex lens which is used to produce a magnified image of an object. The lens is usually mounted in a frame with a handle (see image), a convex lens A lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light, converging or diverging the beam. A simple lens is a lens consisting of a single optical element. A compound lens is an array of simple lenses with a common axis; the use of multiple elements allows more optical aberrations to be corrected forming a magnified image," dates back the Book of Optics The Book of Optics was a seven-volume treatise on optics, physics, mathematics, anatomy and psychology written by the Iraqi Muslim scientist, Ibn al-Haytham (in Europe, Latinized as Alhacen or Alhazen), from 1011 to 1021, when he was under house arrest in Cairo, Egypt published by Alhazen Abū ʿAlī al-Ḥasan ibn al-Ḥasan ibn al-Haytham (Arabic: ابو علي، حسن بن حسن بن الهيثم, Persian: ابن هیثم, Latinized: Alhacen or Alhazen) (965 in Basra - c. 1039 in Cairo), was an Arab or Persian polymath. He made significant contributions to the principles of optics, as well as to anatomy, astronomy, engineering, in 1021. Its translation into Latin The Renaissance of the 12th century saw a major search by European scholars for new learning, which led them to the Arabic fringes of Europe, especially to Islamic Spain and Sicily. A typical story is that of Gerard of Cremona , who was described as having in the 12th century was instrumental to the invention of eyeglasses in 13th century Italy Italy /ˈɪtəli/ (Italian: Italia), officially the Italian Republic (Italian: Repubblica Italiana), is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia. The.[3]

Sunglasses Sunglasses or sun glasses are forms of protective eyewear that usually enclose or protect the eye area in order to prevent strong light from reaching the eyes. They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist which feature lenses that are coloured, polarized or darkened. In the early 20th century, in the form of flat panes of smoky quartz Cairngorm is a variety of smoky quartz crystal found in the Cairngorm Mountains of Scotland. It usually has a smokey yellow-brown colour, though some specimens are a grey-brown, protected the eyes from glare and were used in China China has one of the world's oldest and continuous civilizations, consisting of states and cultures dating back more than six millennia.[citation needed] It has the world's longest continuously used written language system,[citation needed] and is viewed as the source of many major inventions. Historically, China's cultural sphere has extended in the 12th century or possibly earlier. However, they did not offer any corrective benefits.[6]

Invention of eyeglasses

The 'Glasses Apostle' by Conrad von Soest Conrad von Soest, also Konrad in modern texts, or in Middle High German Conrad van Sost or "von Soyst", (born around 1370 in Dortmund; died soon after 1422. He was the most significant Westphalian artist and painted in the so-called soft style of International Gothic. He played a leading role in the introduction of this International (1403)

Around 1284 in Italy, Salvino D'Armate is credited with inventing the first wearable eye glasses.[7] The earliest pictorial evidence for the use of eyeglasses, however, is Tomaso 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 Alpes in an altarpiece of the church of Bad Wildungen, Germany, in 1403.

Many theories abound for who should be credited for the invention of traditional eyeglasses. In 1676, Francesco Redi, a professor of medicine at the University of Pisa, wrote that he possessed a 1289 manuscript whose author complains that he would be unable to read or write were it not for the recent invention of glasses. He also produced a record of a sermon given in 1305, in which the speaker, a Dominican monk named Fra Giordano da Rivalto, remarked that glasses had been invented less than twenty years previously, and that he had met the inventor. Based on this evidence, Redi credited another Dominican monk, Fra Alessandro da Spina of Pisa, with the re-invention of glasses after their original inventor kept them a secret, a claim contained in da Spina's obituary record.[8]

Seated apostle holding lenses in position for reading. Detail from Death of the Virgin, by the Master of Heiligenkreuz, ca. 1400-30 (Getty Center).

Other stories, possibly legendary, credit Roger Bacon with the invention. Bacon is known to have made one of the first recorded references to the magnifying properties of lenses in 1262,[9] though this was predated by Alhazen's Book of Optics in 1021.[3] Bacon's treatise De iride ("On the Rainbow"), which was written while he was a student of Robert Grosseteste, no later than 1235, mentions using optics to "read the smallest letters at incredible distances". While the exact date and inventor may be forever disputed, it is almost certain that spectacles were invented between 1280 and 1300 in Italy. These early spectacles had convex lenses that could correct both hyperopia (farsightedness), and the presbyopia that commonly develops as a symptom of aging. Nicholas of Cusa is believed to have discovered the benefits of concave lens in the treatment of myopia (nearsightedness). However, it was not until 1604 that Johannes Kepler published in his treatise on optics and astronomy, the first correct explanation as to why convex and concave lenses could correct presbyopia and myopia.

Later developments

A portrait of Francisco de Quevedo y Villegas, 1580–1645

The American scientist Benjamin Franklin, who suffered from both myopia and presbyopia, invented bifocals in 1784 to avoid having to regularly switch between two pairs of glasses.[10] The first lenses for correcting astigmatism were constructed by the British astronomer George Airy in 1825.[10]

Over time, the construction of spectacle frames 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 in 1727 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 remained fashionable throughout the 18th and into the early 19th century.

In the early 20th century, Moritz von Rohr at Zeiss (with the assistance of H. Boegehold and A. Sonnefeld[11]), developed the Zeiss Punktal spherical point-focus lenses that dominated the eyeglass lens field for many years.

Despite the increasing popularity of contact lenses and laser corrective eye surgery, glasses remain very common, as their technology has improved. For instance, it is now possible to purchase frames made of special memory metal alloys that return to their correct shape after being bent. Other frames have spring-loaded hinges. Either of these designs offers dramatically better ability to withstand the stresses of daily wear and the occasional accident. Modern frames are also often made from strong, light-weight materials such as titanium alloys, which were not available in earlier times.

Types

Corrective

Seattle skyline as seen through a corrective lens, showing the effect of refraction. Main articles: Corrective lens, Pinhole glasses, and Refraction error

Corrective lenses are used to correct refractive errors of the eye by modifying the effective focal length of the lens in order to alleviate the effects of conditions such as; nearsightedness (myopia), farsightedness (hyperopia) or astigmatism. Another common condition in older patients is presbyopia which is caused by the eye's crystalline lens losing elasticity, progressively reducing the ability of the lens to accommodate (i.e. to focus on objects close to the eye).

The power of a lens is generally measured in diopters. Over-the-counter reading glasses are typically rated at +1.00 to +3.25 diopters. Glasses correcting for myopia will have negative diopter strengths. Prescription lenses, made to conform to the prescription of an ophthalmologist or optometrist, are used to make prescription glasses, which are then verified correct using a professional lensmeter.

Pinhole glasses are a type of corrective glasses which do not use a conventional lens and are claimed to help correct the eye's refractive error without introducing the image distortion of traditional lens-based glasses.

Safety

See also: Eye protection

Safety glasses are usually made with shatter-resistant plastic lenses to protect the eye from flying debris. Although safety lenses may be constructed from a variety of materials of various impact resistance, certain standards suggest that they maintain a minimum 1 millimeter thickness at the thinnest point, regardless of material. Safety glasses can vary in the level of protection they provide. For example, those used in medicine may be expected to protect against blood splatter while safety glasses in a factory might have stronger lenses and a stronger frame with additional shields at the temples. The lenses of safety glasses can also be shaped for correction.

Safety glasses with side shields

The American National Standards Institute has established standard ANSI Z87.1 for safety glasses in the United States, and similar standards have been established elsewhere.

OSHA provides guidance on the type of safety eyewear that should be used for a particular application.

Some safety glasses are designed to fit over corrective glasses or sunglasses. They may provide less eye protection than goggles or other forms of eye protection, but their light weight increases the likelihood that they will actually be used. Modern safety glasses tend to be given a more stylish design in order to encourage their use. Corrective glasses with plastic lenses can be used in the place of safety glasses in many environments; this is one advantage that they have over contact lenses.

There are also safety glasses for welding, which are styled like wraparound sunglasses, but with much darker lenses, for use in welding where a full sized welding helmet is inconvenient or uncomfortable. These are often called "flash goggles", because they provide protection from welding flash.

Worker safety eyewear is available in various lens colors and/or with coatings to protect or enable eyesight in different lighting conditions, particularly when outdoors.

Nylon frames are usually used for protection eyewear for sports because of their lightweight and flexible properties. They are able to bend slightly and return to their original shape instead of breaking when pressure is applied to them. Nylon frames can become very brittle with age and they can be difficult to adjust.

Sunglasses

Main article: Sunglasses

Sunglasses may be made with either prescription or non-prescription lenses that are darkened to provide protection against bright visible light and, possibly, ultraviolet (UV) light. Photochromic lenses, which are photosensitive, darken when struck by UV light.

Light polarization is an added feature that can be applied to sunglass lenses. Polarization filters remove horizontally polarized rays of light, which can cause glare. Polarized sunglasses allow wearers to see into water when normally glare or reflected light would be seen.[12] Polarized sunglasses may present some difficulties for pilots since reflections from water and other structures often used to gauge altitude may be removed, or instrument readings on liquid crystal displays may be blocked.

Yellow lenses increase color contrast and improve depth perception. Brown lenses are common among golfers, but cause color distortion.[citation needed] Blue, purple, and green lenses offer no real benefits to vision enhancement, and are mainly cosmetic.[citation needed] Some sunglasses with interchangeable lenses have optional clear lenses to protect the eyes during low light or night time activities and a colored lens with UV protection for times where sun protection is needed.

Sunglasses are often worn just for aesthetic purposes, or simply to hide the eyes. Examples of sunglasses that were popular for these reasons include teashades and mirrorshades.

3D glasses

The illusion of three dimensions on a two dimensional surface can be created by providing each eye with different visual information. Classic 3D glasses create the illusion of three dimensions when viewing specially prepared images. The classic 3D glasses have one red lens and one blue or cyan lens. 3D glasses made of cardboard and plastic are distributed at 3D movies. Another kind of 3D glasses uses polarized filters, with one lens polarized vertically and the other horizontally, with the two images required for stereo vision polarized the same way. Polarized 3D glasses allow for color 3D, while the red-blue lenses produce a dull black-and-white picture with red and blue fringes.

One kind of electronic 3D spectacles uses electronic shutters, while virtual reality glasses and helmets have separate video screens for each eye. A 3D effect can also be produced using LCD shutter glasses.[13]

Reading glasses

Magnifying lenses which are used to treat mild hyperopia and presbyopia, normally referred to as reading glasses, can be bought off the shelf. Most glasses are made to an individual prescription, based on degree of myopia or hyperopia combined with astigmatism if applicable. Lenses can be ground to specific prescriptions, but in some cases standard off-the-shelf prescriptions suffice, though they require custom fitting to particular frames.

Bifocals, trifocals and progressive lenses

As people age, their ability to focus is lessened and many decide to use multiple-focus lenses, bifocal or even trifocal to cover all the situations in which they use their sight. Traditional multifocal lenses have two or three distinct horizontal viewing areas, each requiring a conscious effort of refocusing. Some modern multifocal lenses, such as progressive lenses (known as "no-line bifocals"), give a smooth transition between these different focal points, unnoticeable by most wearers, while other glasses have lenses specifically intended for use with computer monitors at a fixed distance. People may have several pairs of glasses, one for each task or distance, with specific glasses for reading, computer use, television watching, and writing.

Extreme magnification (bioptics)

A form of glasses with extreme magnification to improve the distance vision of those with severe eyesight impairment, especially people with albinism, are known as bioptics or a bioptic telescope. They may take the form of self-contained glasses that resemble goggles or binoculars, or may be attached to existing glasses.

Fashion

United States senator Barry Goldwater in horn-rimmed glasses.

Glasses can be a major part of personal image and expression, from Groucho Marx and Buddy Holly to the extravagance of Elton John and Dame Edna Everage.

For some celebrities, glasses form part of their identity. United States Senator Barry Goldwater continued to wear lensless horn-rimmed glasses after being fitted with contact lenses because he was not recognizable without his trademark glasses. British soap star Anne Kirkbride had the same problem: her character on Coronation Street, Deirdre Barlow, became so well-known for her big frames that she was expected to wear them at social gatherings and in international tours, even though Kirkbride has always worn contact lenses. Comedian Drew Carey continued to wear glasses for the same reason after getting corrective laser eye surgery. British comedic actor Eric Sykes, who became profoundly deaf as an adult, wears glasses that contain no lenses; they are actually a bone-conducting hearing aid. Masaharu Morimoto wears glasses to separate his professional persona as a chef from his stage persona as Iron Chef Japanese. John Lennon wore his round-lens 'Windsor' spectacles from some of his time with the Beatles to his murder in 1980. The rock band Weezer is known for some of the members wearing thick-rimmed glasses.

Browline glasses were the standard for men in the 1950s and 1960s.

In popular culture, glasses were all the disguise Superman and Wonder Woman needed to hide in plain view as alter egos Clark Kent and Diana Prince, respectively. An example of halo effect is seen in the stereotype that those who wear glasses are intelligent or, especially in teen culture, even geeks and nerds. Some people who find that wearing glasses may look 'nerdy' turn to contact lenses or laser eye surgery, especially under peer pressure.

Another unpopular aspect of glasses is their inconvenience. Even through the creation of light frames, such as those made of titanium, very flexible frames, and new lens materials and optical coatings, glasses can still cause problems during rigorous sports. The lenses can become greasy or trap vapour when eating hot food, swimming, walking in rain or rapid temperature changes (such as walking into a warm building from cold temperatures outside), reducing visibility significantly. Scraping, fracturing, or breakage of the lenses require time-consuming and costly professional repair, though modern plastic lenses are almost indestructible and very scratch-resistant.

Rimless style

Three-piece rimless and semi-rimless glasses are common variations that differ from regular glasses in that their frames do not completely encircle the lenses. Three-piece rimless glasses have no frame around the lenses, and the bridge and temples are mounted directly onto the lenses. Semi-rimless (or half-rimless) glasses have a frame that only partially encircles the lenses (commonly the top portion). When the style was first introduced in the 1930s, lenses were screwed directly to the front of the frame; most modern variations feature the lenses held inside of the frame by high strength nylon wire,[14] although the semi-rimless style has been around since at least the 1940s. A rare and currently noncommercial variation are rimless and frameless glasses attached to a piercing at the bridge of a wearers nose.[15] Such glasses have the visual look of the pince-nez.

Glazing

Spectacle lenses are edged into the frame's rim using glazing machines operated by ophthalmic technicians. The edging process begins with a trace being taken of the frame's eye shape. In earlier days the trace was replicated onto a plastic pattern called a former. Nowadays the process is patternless and the shape is sent to the edger electronically.

The lens, in the form of a round uncut,[clarification needed] is positioned in the correct manner to match the prescription and a block is stuck to the lens and that block fits into a chuck in the edging machine. A diamond-coated wheel spins as the edger replicates the frame's eye-shape to the uncut lens. A V-shaped bevel is applied to allow the edge of the lens to fit into the frame rim.

Redistribution

Some organizations like Lions Clubs International[16] and Unite For Sight[17] provide a way to donate glasses and sunglasses. Unite For Sight has redistributed more than 200,000 pairs.[18]

See also

References

  1. ^ a b DeFranco, Liz (April 2007). "Polycarbonate Lenses: Tough as Nails". All About Vision. http://www.allaboutvision.com/lenses/polycarb.htm. Retrieved on 2007-09-01.
  2. ^ DeFranco, Liz (May 2006). "Do You Need Lens Coatings?". All About Vision. http://www.allaboutvision.com/lenses/coatings.htm. Retrieved on 2007-09-01.
  3. ^ a b c Kriss, Timothy C.; Kriss, Vesna Martich (April 1998), "History of the Operating Microscope: From Magnifying Glass to Microneurosurgery", Neurosurgery 42 (4): 899–907, doi:10.1097/00006123-199804000-00116
  4. ^ Pliny the Elder. "Natural History". http://www.perseus.tufts.edu/cgi-bin/ptext?lookup=Plin.+Nat.+37.16. Retrieved on 2008-04-27.
  5. ^ Dr. Kasem Ajram (1992). Miracle of Islamic Science, Appendix B. Knowledge House Publishers. ISBN 0911119434.
  6. ^ Ament, Phil (2006-12-04). "Sunglasses History - The Invention of Sunglasses". The Great Idea Finder. Vaunt Design Group. http://www.ideafinder.com/history/inventions/sunglasses.htm. Retrieved on 2007-06-28.
  7. ^ Bellis, Mary. "The History of Eye Glasses or Spectacles". About.com:Inventors. http://inventors.about.com/od/gstartinventions/a/glass_3.htm. Retrieved on 2007-09-01.
  8. ^ "Famous Historical Statements up to 1600". Antique Spectacles. http://www.antiquespectacles.com/statements/1600.htm. Retrieved on 2007-09-01.
  9. ^ "....Optics Highlights: II. Spectacles". University of Maryland, Department of Electrical & Computer Engineering. http://www.ece.umd.edu/~taylor/optics2.htm. Retrieved on 2007-09-01.
  10. ^ a b Bellis, Mary. "The Inventions and Scientific Achievements of Benjamin Franklin". http://inventors.about.com/od/fstartinventors/ss/Franklin_invent_4.htm. Retrieved on 2007-09-01.
  11. ^ "Eyeglass Lenses and Visual Aids from Industrial Production". Zeiss.com. http://www.zeiss.com/C12567A100537AB9/Contents-Frame/6B49EEA709EAE719C1256919003DAE2B. Retrieved on 2007-09-02.
  12. ^ "Sunglasses Glossary". SunGlassesUK.com. http://www.sunglassesuk.com/sunglasses_glossary.asp. Retrieved on 2009-04-23.
  13. ^ "Technologies for Consumer 3D Anatomical Interactivity". OCB Media. 1st October 2008. http://www.ocbmedia.com/news/56/Technologies-for-Consumer-3D-Anatomical-Interactivity/. Retrieved on 2009-01-26.
  14. ^ O'Keefe, Jackie (July/August 2003). "The Newest Technologies in Rimless Eyewear". Vision Care Product News. http://www.visioncareproducts.com/CE-old/frames_newest.html. Retrieved on 2006-01-09.
  15. ^ "Pierced Glasses". http://www.piercedglasses.com/mark2.html. Retrieved on 2007-08-07.
  16. ^ Lions Clubs International. "Lions Eyeglasses Recycling Facts " received 20 August 2008.
  17. ^ Unite For Sight "Donate Eyeglasses and Sunglasses" received on 20 August 2008.
  18. ^ "2007 BRICK Award Winner: Jennifer Staple" HowStuffWorks 20 February 2007, received 20 August 2008.

External links

Listen to this article (info/dl) This audio file was created from a revision dated 2008-03-31, and does not reflect subsequent edits to the article. (Audio help) More spoken articles
Wikiquote has a collection of quotations related to: Glasses
Wikimedia Commons has media related to: Glasses
Look up spectacles or glasses in Wiktionary, the free dictionary.
Type of glasses
Historical Lorgnette · Monocle · Pince-nez · Scissors-glasses
Modern Browline · Bug eye · Cat eye · GI glasses · Horn-rimmed
Sunglasses Aviator · Glacier · Mirrored · Teashades · Shutter Shades · Wayfarer

Categories: Corrective lenses

 

The above information uses material from Wikipedia and is licensed under the GNU Free Documentation License.
Some facts may not have been fully verified for accuracy. [Disclaimers]
This page was last archived by our server on Tue Jul 7 00:49:32 2009. [ refresh local cache ]
Displaying this page or its contents does not use any Wikimedia Foundation's resources.
The owners of this site proudly support the Wikimedia Foundation.

[Hide]▼
'Glasses' News
Alec Baldwin's huge 'Prelude to a Kiss' glasses: Are they making a ... - Entertainment Weekly
news.google.com
Alec Baldwin's huge 'Prelude to a Kiss' glasses : Are they making a ...

Entertainment Weekly

I knew big round glasses were back, but man, they are eh-heverywhere. I see them on the street (though I'm asking for it, I guess; I live in Brooklyn), ...
Google News Search: Glasses,
Fri Jul 10 08:10:24 2009
'Glasses' Images
glasses jpg
hopelyn.com
glasses jpg
375px x 500px | 37.10kB

[source page]

Glasses

Yahoo Images Search: Glasses,
Fri Jul 10 04:16:59 2009
'Glasses' Blogs
Another Perfectly Imperfect Life: Mick Hawking MREA Beer Glasses
ianwoof.blogspot.com
Another Perfectly Imperfect Life: Mick Hawking MREA Beer Glasses

Ian Woofenden

hu, 18 Jun 2009 23:28:00 GM

Mick Hawking MREA Beer . Glasses. . Posted by Ian Woofenden at 4:28 PM Newer Post Older Post Home. E-Mail Me. I'd love to have your thoughts, response, critique, whatever. Just e-mail me at ...

Google Blogs Search: Glasses,
Sat Jun 20 17:09:28 2009
'Glasses' Answers
How do my glasses get so dirty?
Q. I have glasses that I use just for my laptop, which I keep in their case when not in use. How can the lenses get dirty when they have not been exposed to the elements? This puzzles me. Do you have an explanation?
Asked by marygirl - Thu Feb 23 17:56:19 2006 - - 4 Answers - 0 Comments

A. Static electricity, or, they might have oil on them that you can't see, it attracts the dirt and fuzz and dust.
Answered by BfrombigD - Thu Feb 23 17:57:27 2006

Yahoo Answers Search: Glasses,
Sat Jul 4 11:38:46 2009
[Hide]▲