what materials were originally used to make eyeglasses?
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Glass was the original material for spectacles because it has great optical clarity, but the glass lenses can be very heavy in stronger prescriptions. Plastic lenses are much lighter than glass but they are prone to easily being scratched.
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['Glazing.', 'Aluminium.', 'Stainless steel.', 'Zinc.', 'Composites.', 'Timber.', 'Tensile fabric coverings.', 'Brick slips.']
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Architectural glass is glass that is used as a building material. It is most typically used as transparent glazing material in the building envelope, including windows in the external walls. Glass is also used for internal partitions and as an architectural feature.
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Glass is much more scratch resistant than plastic, making the glasses last longer. ... Glass lenses generally have a higher index than plastic lenses, making them slightly thinner and more attractive looking.
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A lens is a shaped piece of transparent glass or plastic that refracts light. When light is refracted it changes direction due to the change in density as it moves from air into glass or plastic. Lenses are used in cameras, telescopes, binoculars, microscopes and corrective glasses. A lens can be convex or concave .
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In different regions of the world, eyeglasses with very thick lenses in the frame are called "Coke bottle" glasses -- named after the thick bottoms of Coca-Cola contour bottles. Coke-bottle glasses and beer bottle glasses are both American-English expressions.
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The AcrySof® Toric lens is made of the same biocompatible lens material already successfully implanted in more than 25 million eyes since 1991. Toric IOL technology uses biocompatible materials that have been successfully used in contact lenses and proven safe for the eye.
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Rimless eyeglasses, are a type of eyeglasses in which the lenses are mounted directly to the bridge and/or temples. ... Rimless glasses were a popular style of eyeglasses from the 1880s until into the 1960s, and re-emerged in popularity in the latter part of the 20th century and early 21st century.
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Glass is made from natural and abundant raw materials (sand, soda ash and limestone) that are melted at very high temperature to form a new material: glass.
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The first telescopes were obviously of inferior quality, and had simple lenses instead of doublets which reduce chromatic abberation. They also had a concave eyepiece (like opera glasses) which give an erect image, while modern telescopes usually have convex eyepieces and an inverted image.
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['Plastics. Plastics are organic polymeric materials that can be molded into the desired shape. ... ', 'Metals (steel, tin, aluminum) ... ', 'Glass. ... ', 'Wood, cardboard and papers. ... ', 'Advances in packaging techniques.']
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Correct Option: C A type of glass that contains cerium and other rare earths and has a high absorption of ultraviolet radiation is used in sunglasses.
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Rimless Eyeglasses Trends Rimless eyeglasses are classically retro with a stylishly intellectual vibe, but through the use of modern textures and sleek design elements, you'll find a few styles that bridge the gap between old and new. Enterprise's sleek rectangular lenses give it an in-style, classic feel.
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['Frame front. This is the main part of your glasses frame. ... ', 'Endpieces. At the outermost edges of your frame front, are the glasses endpieces. ... ', 'Bridge. What is the bridge on glasses? ... ', 'Lenses. ... ', 'Temples. ... ', 'Temple tips. ... ', 'Hinges. ... ', 'Screws.']
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Most of the beads were made of glass, a material previously unknown to the Native cultures. They often replaced Indian-made beads of bone, shell, copper and stone. Beads were important for early trade items because they were compact and easily transportable.
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['Scientific Tools. Name of. ... ', 'Goggles Used to protect your eyes. ... ', 'Microscope Allows you to see very small things in detail. ... ', 'Calculator Used to figure out amounts or totals. ... ', 'Graduated cylinder Used to measure the volume of a liquid. ... ', 'Binoculars. ... ', 'Forceps Used to pick up tiny objects to view with a magnifying glass.']
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Glass spectacle lenses They still have their place in optometry today thanks to their exceptional scratch resistance. Consumers will also like the fact that they are also less expensive than comparable plastics.