About Sunglasses – Gkboptical.com Sunglasses or sun glasses are a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes. In the early 20th century they were also known as sun cheaters

History of Sunglasses In prehistoric and historic time, Inuit people wore flattened walrus ivory "glasses," that came with narrow slits that block harmful rays of the sun. First Sunglass in History Which Protect the eyes from Snow…. Inuit snow goggles function by reducing exposure to sunlight, not by reducing its intensity

Modern developments In the early 1900s, the use of sunglasses started to become more widespread, especially among movie stars. It is commonly believed that this was to avoid recognition by fans, but an alternative reason sometimes given is that they often had red eyes from the powerful arc lamps that were needed due to the extremely slow speed film stocks used Foster in Foster found a ready market on the beaches of Atlantic City, New Jersey, where he began selling sunglasses under the name Foster Grant from a Woolworth on the Boardwalk

Visual clarity and comfort  Sunglasses can improve visual comfort and visual clarity by protecting the eye from glare.  Various types of disposable sunglasses are dispensed to patients after receiving mydriatic eye drops during eye examinations.  The lenses of polarized sunglasses reduce glare reflected at some angles off shiny non-metallic surfaces such as water. They are popular among fishermen because they allow wearers to see into water when normally only glare would be seen.  The glare is neutralized by blocking the vertical (magnetic) components of light. Functions of Sunglasses

Protection of Eyes from many Factors  Sunglasses offer protection against excessive exposure to light, including its visible and invisible components.  The most widespread protection is against ultraviolet radiation, which can cause short-term and long-term ocular problems  High-energy visible light (HEV) has been implicated as a cause of age-related macular degeneration. before, debates had already existed as to whether "blue blocking" or amber tinted lenses may have a protective effect.  Sunglasses are especially important for children, as their ocular lenses are thought to transmit far more HEV light than adults Functions of Sunglasses

Assessing the protection of sunglasses  The only way to assess the protection of sunglasses is to have the lenses measured, either by the manufacturer or by a properly equipped optician.  Several standards for sunglasses allow a general classification of the UV protection.  Manufacturers often indicate simply that the sunglasses meet the requirements of a specific standard rather than publish the exact figures. Functions of Sunglasses

Further functions of sunglasses  Sunglasses can also be used to hide emotions; this can range from hiding blinking to hiding weeping and its resulting red eyes.  Fashion trends can be another reason for wearing sunglasses, particularly designer sunglasses  People may also wear sunglasses to hide an abnormal appearance of their eyes.  Fashion trends can also draw on the "cool" image of sunglasses.  Some lawbreakers have also been known to wear sunglasses during or after committing a crime as an aid to hiding their identities. Functions of Sunglasses

There are three major sunglass standards, which are popularly known mostly as a reference for sunglass protection from UV radiation  The Australian Standard is AS/NZS 1067:2003 Sunglasses and fashion spectacles. The five ratings for transmittance (filter) under this standard are based on the amount of absorbed light  The European standard EN 1836:2005 has four transmittance ratings: "0" for insufficient UV protection, "2" for sufficient UHV protection, "6" for good UHV protection  The U.S. standard is ANSI Z , which includes three transmittance categories. According to the ANSI Z standard Standards for sunglasses

Special use sunglasses Sunglasses in Sports - Sunglasses have to meet special requirements when worn for sports. Strap or other fixing is typically used to keep glasses in place during sporting activities, and they have a nose cushion. Mountain climbing or traveling across glaciers or snowfields requires above-average eye protection, because sunlight (including ultraviolet radiation) is more intense in higher altitudes, and snow and ice reflect additional light. Popular glasses for this use are a type called glacier glasses or glacier goggles. They typically have very dark round lenses and leather blinders at the sides, which protect the eyes by blocking the sun's rays around the edges of the lenses.

Special-use sunglasses Sunglasses in space - Special protection is required for space travel because the sunlight is far more intense and harmful than on Earth, where it is always filtered through the atmosphere. Sun protection is needed against much higher UV radiation and even against harmful infrared radiation, both within and outside the spacecraft. Within the spacecraft, astronauts wear sunglasses with darker lenses and a thin protective gold coating. During space walks, the visor of the astronauts' helmets, which also has a thin gold coating for extra protection, functions as strong sunglasses

Aviator sunglasses - are a style of sunglasses that were developed by Bausch & Lomb and branded as Ray-Ban. They are characterized by dark, often reflective lenses having an area two or three times the area of the eyeball, and very thin metal frames with double or triple bridge and bayonet earpieces or flexible cable temples that hook behind the ears. The original design featured G-15 tempered glass lenses, i.e., neutral gray, transmitting 20% of incoming light. The large lenses are not flat but slightly convex. The design attempts to cover the entire range of the human eye and prevent as much light as possible from entering the eye from any angle Aviator sunglasses, or "pilot's glasses", were originally developed in 1936 by Ray-Ban for pilots to protect their eyes while flying. Type Of Sunglasses

Mirrored sunglasses - Mirrored lenses, having a metallic, partially reflective coating on the outer surface, combined with a tinted glass lens, are an alternative to polarization for UV protection, improving contrast when depth perception is important such as seeing moguls and ice while skiing or snowboarding. The mirrored lens reflects glare to protect the eyes, but improves the ability to see contrasts, and mirrored lenses of different colors can expand the range of fashion styles.

Type Of Sunglasses Oversized sunglasses - Oversized sunglasses, which were fashionable in the 1980s, are now often used for humorous purposes. They usually come in bright colors with colored lenses and can be purchased cheaply. Singer Elton John sometimes wore oversized sunglasses on stage in the mid-1970s as part of his Captain Fantastic act. In the early 21stcentury moderately oversized sunglasses had become a fashion trend. There are many variations, such as the "Onassis", discussed below, and Dior white sunglasses.

Type Of Sunglasses Teashades - "Teashades" (sometimes also called "John Lennon glasses", "Round Metal", or, occasionally, "Granny Glasses") were a type of psychedelic art wire-rim sunglasses that were often worn, usually for purely aesthetic reasons, by members of the 1960s counterculture, as well as by opponents of segregation. Pop icons such as Mick Jagger, Roger Daltrey, John Lennon, Jerry Garcia, Boy George, Liam Gallagher and all wore teashades. The original teashade design was made up of medium-sized, perfectly round lenses, supported by pads on the bridge of the nose and a thin wire frame. When teashades became popular in the late 1960s

Type Of Sunglasses Wayfarers - The Ray-Ban Wayfarer is a plastic-framed design for sunglasses produced by the Ray-Ban company. Introduced in 1952, the trapezoidal lenses are wider at the top than the bottom and were famously worn by James Dean, Roy Orbison and other actors and singers. The original frames were black; frames in many different colors were later introduced. There is always a silver piece on the corners as well.

Type Of Sunglasses Wrap-around sunglasses - Wrap-arounds (sometimes also called "Yoko Ono glasses") are a specific design of sunglasses. They are characterized by a single, smooth, semi- circular lens that covers both eyes and much of the same area of the face covered by protective goggles. The lens is usually combined with a minimal plastic frame and single piece of plastic serving as a nosepiece. As an alternative, the glasses can have two lenses, but the design evokes the same semicircle.