Glasses

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Glasses , also known as sunglasses or glasses is a device which consists of glass or hard plastic lenses mounted in a frame that holds it in front of one's eyes, usually using a bridge over the nose and the arm that lies above the ear.

Glasses are usually used for vision correction, such as reading glasses and glasses used for farsightedness.

Safety goggles provide eye protection against flying debris for construction workers or laboratory technicians; these glasses may have protection for the side of the eye as well as on the lens. Some types of safety goggles are used to protect against visible and almost visible light or radiation. Glasses are used for eye protection in some sports, such as squash.

Eyeglass wearers can use the rope to prevent glasses from falling during movement or exercise. Users of glasses used only part of the time may have goggles attached to the rope that surrounds their necks, to prevent loss of glasses and rupture.

Sunglasses allow better eyesight during sunny days, and can protect a person's eyes against damage from high-level ultraviolet rays. Typical sunglasses darkened for protection against bright light or glare; some special glasses are clear in dark or indoor conditions, but turn into sunglasses when in bright light. Most of the sunglasses do not have corrective strength in the lens; However, special prescription glasses can be ordered.

Special glasses can be used to view certain visual information, such as 3D glasses for 3D movies (stereoscopy). Sometimes glasses are worn solely for fashion or aesthetic purposes. Even with the glasses used for vision correction, various modes are available, using plastic, wire, and other materials.

People are more likely to need the older glasses they get with 93% of people between the ages of 65-75 using corrective lenses.

Video Glasses

Type

Glasses can be marked or discovered by their main function, but also appear in combinations such as prescription glasses or safety glasses with enhanced magnification.

Corrective

Corrective lenses are used to correct bias errors by bending the incoming light into the eye to reduce the effects of conditions such as myopia, myopia (hypermetropia) or astigmatism. The ability of one's eyes to accommodate their focus to focus closely and away from time to time. A common condition in people over forty is presbyopia, caused by eye lenses that lose eye elasticity, which progressively reduces the ability of the lens to accommodate (ie focus on objects close to the eye). Few people have a pair of eyes that exhibit exactly the same refractive characteristics; one eye may require a "stronger" lens (ie more refraction) than the other.

Corrective lens brings the image back to focus on the retina. They are made to suit the prescription of an ophthalmologist or ophthalmologist Lensmeter can be used to verify specifications of existing pair of glasses. Corrective sunglasses can significantly improve the quality of life of the wearer. Not only improves the visual experience of the wearer, it can also reduce the problems caused by eye strain, such as headache or squinting.

The most common type of corrective lens is "single vision", which has a uniform refractive index. For people with presbyopia and hyperopia, bifocal and trifocal glasses provide two or three different refractive indexes, respectively, and progressive lenses have a continuous gradient.

The reading glasses provide separate glasses to focus on nearby objects. Reading glasses are available without a prescription from a drug store, and offer a cheap practical solution, although it has a pair of simple lenses of the same strength, so it will not fix refraction problems like astigmatism or variations in bias or prism between the left and right eyes. For a total correction of individual views, the glasses corresponding to the recent ophthalmic prescription are required.

Glasses with adjustable focus can be used to replace bifocals or trifocals, or can be used to produce cheaper vision glasses (because they do not have to be tailor-made for everyone).

Pinhole glasses are a type of corrective glasses that do not use lenses. Pinhole glasses do not really refract light or change the focal length. Instead, they create a finite diffraction system, which has an increased depth of field, similar to using a small aperture in photography. This form of correction has many limitations that prevent it from gaining popularity in everyday use. Pinhole glasses can be made by DIY by making a small hole in a card that is then held in front of the eyes with a rope or cardboard sleeve.

Security

Safety glasses are used to protect the eyes in different situations. They are made with a break-proof plastic lens to protect the eyes from flying debris or other materials. Construction workers, factory workers, engineers and laboratory technicians are often asked to wear safety goggles to protect the eyes from flying debris or dangerous splashes such as blood or chemicals. In 2017, dentists and surgeons in Canada and other countries are required to wear safety goggles to protect against infections from the patient's blood or other body fluids. There are also safety glasses for welding, arranged like sunglasses cover, but with darker lenses, for use in welding where full-sized welded helmets are uncomfortable or uncomfortable. These are often called "flash goggles", as they provide protection from flash welding. Nylon frame is usually used for protective goggles for sport because of its light and flexible nature. Unlike most ordinary glasses, safety glasses often include protection on the side of the eye and in front of the eyes.

Sunglasses

Glasses provide better comfort and protection against bright light and often against ultraviolet (UV) rays. To protect the eyes well from the dangers of UV rays, sunglasses must have UV-400 blockers to provide good protection against the entire spectrum of harmful light. Photochromic lenses, which are photosensitive, darken when exposed to UV rays. The dark color of the lens in a pair of sunglasses blocking the transmission of light through the lens.

Light polarization is an additional feature that can be applied to a sunglass lens. The polarization filter is positioned to remove horizontal light polarized light, which removes glare from the horizontal surface (allowing the user to see into the water when the reflected light reverse will flood the scene). Polarized sunglasses may present some difficulty for the pilot because reflections from water and other structures often used to measure altitude can be eliminated. Liquid crystal displays often emit polarized light making them sometimes difficult to see with polarized glasses. Sunglasses can be worn only for aesthetic purposes, or just to hide the eyes. Examples of popular sunglasses for this reason include teashades and mirrorshades. Many blind people wear almost opaque glasses to hide their eyes for cosmetic reasons.

Sunglasses may also have corrective lenses, which require a prescription. Clip-on sunglasses or sunglass clips can be attached to a pair of other glasses. Some sunglasses are wrapped big enough to be worn on top of other glasses. Otherwise, many people choose to wear contact lenses to improve their eyesight so that standard sunglasses can be used.

3D glasses

Three-dimensional illusions on two-dimensional surfaces can be made by providing each eye with different visual information. 3D glasses create a three-dimensional illusion by filtering signals that contain information for both eyes. The signal, often reflected light from the film screen or emitted from the electronic screen, is filtered so that each eye receives a slightly different image. The filter only works for the type of signal designed for it.

Anaglyph 3D Glasses have different color filters for each eye, usually red and blue or red and green. The polarized 3D system on the other hand uses polarized filters. Polarized 3D glasses allow for 3D color, while blue-red lenses produce images with distorted color. The active 3D shutter system uses electronic shutters. Head-mount displays can filter signals electronically and then send light directly to the eyes of the viewer.

Anaglyph and polarized glasses are distributed to audiences in 3D movies. Shutter glasses polarized and actively used with many home theaters. Head-mount displays are used by one person, but input signals can be shared between multiple units.

Enlargement (bioptics)

Glasses can also provide useful enlargements for people with visual impairments or specific job demands. An example is a bioptic or bioptic telescope that has a small telescope mounted in, in, or behind their regular lens. Newer designs use smaller lightweight telescopes, which can be embedded into corrective glass and enhance aesthetic appearance (mini telescopic glasses). They can take the form of independent glasses that resemble glasses or binoculars, or may be attached to the existing glasses.

yellow/yellow computer/game glasses

Yellow glasses are the type of glasses with a minor yellow color. They do minor color corrections, above reducing headaches due to lack of flicker. They can also be considered as small sunglasses that are not corrected corrective. Depending on the company, the computer or gaming glasses can also filter out blue light and ultra-violet high energy from LCD screens, fluorescent lamps, and other light sources. This makes it possible to reduce eye strain. These glasses can be ordered as standard lenses or prescription lenses that match the standard optical frames. Because ultra-violet light blocks the properties of these lenses, they also help the user sleep at night along with decreasing age-related macular degeneration.

Anti-glare protection glasses

Anti-glare protective goggles, or anti-reflective glasses, can reduce the reflection of light coming into our eyes. The lens is given an anti-glare coating to prevent reflections of light under different lighting conditions. By reducing the amount of glare on your eyes, vision can be improved. Anti-glare also applies to the outer glass, making it possible for better eye contact.

Maps Glasses

Frames

The eye frame is part of a pair of glasses designed to hold the lens in the right position. Ophthalmic frames come in different styles, sizes, materials, shapes, and colors.

Section

• a pair of eye or rim wires that surround and hold the lens in place
• a bridge connecting two eye cables
• chassis, combination of eye cable and bridge
• the top bar or brow bar, the bar just above the bridge provides structural support and/or style enhancement. The addition of the top bar makes a pair of aviator sunglasses glasses
• a pair of eyebrows or lids, plastic or metal caps that match the top of the eye cable for style enhancement and to provide additional support for the lens. The addition of eyebrows makes pair eyewear glasses paired
• a pair of nose pads that allow a comfortable break from eye wires on the nose
• pair of arm pad connecting nose pad to eye cable
• a pair of temples (earpieces) on both sides of the skull
• a pair of the ends of the temple at the end of the temple
• a pair of end pieces connecting an eye cable through a hinge to the temple
• a pair of front-end frames
• a pair of hinges connecting the tip piece to the temple, allowing a circular motion. Flexible spring hinges are variants equipped with small springs that give the temples a greater range of motion and do not limit them to traditional 90-degree angles. Improvements can be made using the Self Spring Spring Screw Hinges. Use a screw insertion pliers to push the ends outside the first barrel of the spring hinge at a 45-degree angle and use a standard screwdriver to tighten. When the screw moves down the barrel, it will move to a 90 degree angle. Once done, use the plier to decide the excess.

Temple type

• Temple of the skull: leaning behind the ear, following the contours of the skull and resting evenly over the skull
• Temple of the library: generally straight and not bent behind the ear. Hold the glass primarily through light pressure on the skull side
• Convertible temples: used either as libraries or skull temples depending on the crook
• Down the arc: curves around the ears and extends to the ear lobe level. Used mainly on the athletic, child, and industry safety frames;
• Convenient cable temples: similar to horseback, but made of circular, circular metal wires, sometimes inside plastic or silicone sleeves. Curly tension can be adjusted along its length, allowing the frame to fit perfectly into the wearer's ear. Used for physically active users, children, and people with high prescription (heavy lens). See frame picture 1920 above.

Materials

Plastic and polymer

• Cellulose acetate
• Optyl, a hypoallergenic material specially made for eyeglass frames. It has a type of elasticity that returns the material to its original shape.
• Cellulose propionate, molded and durable plastic
• Plastic 3D prints using super-fine polyamide powder and Selective Sintering Laser process - see Mykita Mylon (Please also note that 3-D printable frames with fused filament fused for ABS, PLA or nylon money)
• Nylon

Metal

• Gold
• Silver
• Aluminum
• Beryllium
• Stainless Steel
• Titanium
• Flexon

Natural materials

• Wood
• Bone
• Ivory
• Skin
• Semi-precious or precious stones

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Corrective lens shape

Corrective lenses can be produced in different shapes from circular lenses called empty lenses. The empty lens is cut to fit the frame shape that will hold it. Frame styles vary and fashion trends change over time, resulting in many lens shapes. For low-power lenses, there are some limitations that allow for many trendy and fashionable shapes. Higher power lenses can cause distortion of peripheral vision and can become thick and heavy if large lens shapes are used. However, if the lens becomes too small, the field of view can be drastically reduced.

Bifocal, trifocal, and progressive lenses generally require higher lens shapes to leave space for different segments while maintaining an adequate field of vision through each segment. Frames with rounded edges are the most efficient for correcting myopic recipes, with perfect round frames being the most efficient. Before the advent of sunglasses as a fashion item, when frames were built only with functions in mind, almost all glasses were round, oval, or octagon curved. It was not until glasses began to be seen as accessories that different shapes were introduced to be more aesthetic than functional.

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History

Precursors

The evidence is available for the use of visual aids in Greek and Roman times, which is most evidently the use of emeralds by emperor Nero as mentioned by Pliny the Elder.

The use of convex lenses to form enlarged/enlarged images is most likely described in Ptolemy Optics (which however survive only in poor Arabic translations). The description of Ptolemy's lens is commented upon and corrected by Ibn Sahl (10th century) and especially by Alhazen ( Book of Optics, ca. 1021). The Latin translations of Ptolemy Optics and Alhazen became available in Europe in the 12th century, coinciding with the development of "reading stones".

Robert Grosseteste's [i> De iride ("On the Rainbow"), written between 1220 and 1235, mentions using optics to "read the smallest letter at great distances". A few years later in 1262, Roger Bacon was also known to have written about the magnifying properties of the lens. The development of the first glasses occurred in Northern Italy in the second half of the 13th century.

Independently from the development of optical lenses, some cultures develop "sunglasses" for eye protection, without corrective properties. Thus, smoky quartz flat panels, used in 12th century China. Similarly, Inuit has been using snow goggles for eye protection.

Discovery

The first glasses were made in Northern Italy, most probably in Pisa, circa 1290: In a sermon delivered on 23 February 1306, the Dominican monk Giordano da Pisa (ca. 1255-1311) wrote, "Not yet twenty years since then, make glasses, that make good vision... And it's so short that this new art, never before, was found... I saw the man who first discovered and practiced it, and I spoke with him. "

Giordano's partner, Friar Alessandro della Spina of Pisa (d. 1313) immediately made glasses. The Ancient Note of the Dominican Convent St. Catherine di Pisa notes: "Glasses, first made by others, who do not want to share them, he [Spina] makes and shares them with everyone with a cheerful and sincere heart." In 1301, there were union rules in Venice which governs the sale of glasses.

The earliest pictorial evidence for the use of spectacles is a portrait of 1352 Tommaso da Modena on the reading of the cardinal Hugh de Provence in the scriptorium. Another early example is the depiction of glasses found in the northern Alps at the altar of the church of Bad Wildungen, Germany, in 1403. These early glasses have convex lenses that can correct both hyperopia (farsightedness), and generally developed presbyopia. as symptoms of aging. It was not until 1604 that Johannes Kepler published the first correct explanation of why convex and concave lenses can improve presbyopia and myopia.

The initial frame for the glasses consists of two magnifying glasses glued together by the handle so that they can grip the nose. These are referred to as "rivet eyeglasses". The earliest surviving examples are found beneath the floor boards at Kloster Wienhausen, a monastery near Celle in Germany; they have been dated to around 1400.

More claims

Claims that Salvino degli Armati of Florence find glasses have been exposed as hoaxes.

Marco Polo has occasionally claimed to have discovered eyeglasses during his travels in China in the 13th century, however, no such statements appear on his account. Indeed, the earliest mention of glasses in China occurred in the 15th century and Chinese sources claimed that glasses were imported.

It is sometimes also claimed that glasses were first discovered in India. In 1907 Professor Berthold Laufer declared in his history of the glasses that "the idea that glasses originated in India is the greatest possibility and that the glasses must have been known in India earlier than in Europe." However, Joseph Needham points out that the mention of sunglasses in the Laufer texts used to justify earlier findings from them in Asia does not exist in the older versions of the manuscript, and a reference to them in later versions was added during the Ming dynasty. In a 1971 article in the British Journal of Ophthalmology, he argues that: "... therefore it is likely that the use of lenses reached Europe through Arabia, as well as Hindu mathematics and ophthalmological works of ancient Hindu. Susruta ", but all dates were given well after the presence of glasses in Italy was established, and there has been a significant shipment of eyeglasses from Italy to the Middle East, with a single delivery of 24,000 glasses.

Next development

American scientist Benjamin Franklin, who suffers from myopia and presbyopia, finds a bifocal. Serious historians from time to time produce evidence to suggest that others may have preceded it in this discovery; However, the correspondence between George Whatley and John Fenno, the editor of the US Gazette, suggests that Franklin did indeed find glasses, and perhaps 50 years earlier than originally thought. The first lens to correct astigmatism was designed by British astronomer George Airy in 1825.

Over time, the development of frames for eyeglasses also evolved. Early eyepieces are designed to be held by hand or by putting pressure on the nose ( pince-nez ). Girolamo Savonarola suggests that eyepieces can be held in place by the tape that passes through the head of the wearer, this in turn is guaranteed by the weight of the cap. The modern style of glasses, held by a temple passing through the ears, was developed some time before 1727, possibly by the English eyewear expert Edward Scarlett. This design did not immediately succeed, however, and various styles with inherent grips such as "scissors-glasses" and lorgnettes were also fashionable from the second half of the 18th century and into the early 19th century.

At the beginning of the 20th century, Moritz von Rohr and Zeiss (with the help of H. Boegehold and A. Sonnefeld), developed the Zeiss Punktal round focus lens that dominated the spectacle lens field for years. In 2008, Joshua Silver designed the glasses with customizable corrective glasses. They work with silicone fluids, syringes, and pressure mechanisms.

Despite the growing popularity of contact lenses and laser corrective eye surgery, glasses remain very common, as their technology has improved. For example, it is now possible to buy a frame made from a special memory metal alloy that returns to its correct shape after being bent. Another frame has a spring hinge. One of these designs offers a much better ability to withstand the pressure of everyday clothes and occasional crashes. Modern frames are also often made of strong lightweight materials such as titanium alloys, which were not available in earlier times.

In

mode

In the 1930s, "glasses" was described as "medical equipment." Wearing glasses is sometimes considered socially shameful. In the 1970s, fashionable glasses became available through manufacturers, and the government also recognized the demand for stylish glasses.

Graham Pullin describes how devices for disability, such as glasses, are traditionally designed to disguise skin and restore capabilities without being seen. In the past, designs for disability have been "less about projecting positive images such as about trying not to project a picture at all." Pullin uses an example of glasses, traditionally categorized as a "patient" medical device, and describes how they are now described as glasses: fashionable accessories. Just like other fashion designs and accessories, sunglasses are made by designers, have leading labels, and are present in collections, based on season and designers. It is becoming more common for consumers who buy glasses with clear and unspecified lenses, which illustrate that glasses are no longer a social stigma, but a fashionable accessory that "frames your face."

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Society and culture

Market

The market for eyeglasses has been characterized as having a very inelastic demand, and ad restrictions in the US have correlated with higher prices, suggesting that advertising makes the eyewear market more competitive in price. It may also be monopolistic competition.

There are claims that free-market competition is not enough to inflate frame rates, which cost an average of $ 25- $ 50 US to make, with an average retail price of $ 300 in the United States. This claim is denied by some in the industry. (See also Luxottica # Criticism.)

Redistribution

Some organizations such as Lions Clubs International, Unite For Sight, ReSpectacle, and New Eyes for the Needy provide a way to donate spectacles and sunglasses. Unite For Sight has distributed over 200,000 pairs.

Mode

Many people need glasses for the reasons listed above. There are many shapes, colors, and materials that can be used when designing frames and lenses that can be used in various combinations. Often, the selection of a frame is based on how it will affect the wearer's appearance. Some people with good natural eyesight want to wear glasses as stylish accessories.

Personal image

For much of their history, glasses are viewed as outdated, and carry some potentially negative connotations: wearing glasses causes individuals to be stigmatized and stereotyped as godly pastors (for they in religious vocations are the most likely to be literate and therefore most likely to need reading glasses), elderly, or physically and passively weak. The stigma began to fall out in the early 1900s when the popular Theodore Roosevelt was regularly photographed wearing glasses, and in 1910 when the famous comedian Harold Lloyd began wearing a pair of horn-rimmed glasses as a "Glasses" character in his films.

Since, glasses have become acceptable fashion items and often act as a key component in an individual's personal image. Musicians Buddy Holly and John Lennon become synonymous with the style of glasses they wear to a thick point, horn-rimmed sunglasses are often called "Buddy Holly glasses" and a perfectly rounded frame of metal glasses called "John Lennon (or Harry Potter) Glasses." English comedy Eric Sykes is known in the UK for wearing thick, square, horn-rimmed glasses, which is actually a sophisticated hearing aid that relieves his deafness by allowing him to "hear" vibrations. Some celebrities have become so closely related to their glasses that they continue to wear them even after taking an alternative step towards vision problems: US Senator Barry Goldwater and comedian Drew Carey continue to wear non-prescription glasses after being installed for contact and undergo laser eye surgery, respectively.

Other celebrities have used glasses to distinguish themselves from the characters they play, such as Anne Kirkbride, who wears oversized, 1980s-style horned spectacles like Deirdre Barlow on the soap opera Coronation Street and Masaharu. Morimoto, who wore glasses to separate his professional persona as a chef from his stage persona as a Japanese Iron Chef. In 2012 some NBA players wear glasses without lenses with thick plastic frames such as horn-rimmed glasses during post-match interviews, geek chic that draw comparisons with Steve Urkel.

In superhero fiction, glasses have become a standard component of the various disguises of heroes (as masks), allowing them to adopt an obscure attitude when they are not in their superhero persona: Superman is famous for wearing rimmed 1950s-style horn frames like Clark Kent, Wonder Woman wore sunglasses, Harold Lloyd sunglasses, or bug-eye glasses of the 1970s as Diana Prince. Examples of halo effects are seen in the stereotype that those who wear smart glasses.

Style

Source of the article : Wikipedia