When did humans start to improve vision?
🔎 Scientists suppose that the first vision aid, called a reading stone, was invented around 1000 AD. The reading stone was a glass sphere that was laid on top of the reading material to magnify the letters.
🔎 One of the earliest historical reference to magnification dates back to ancient Egyptian hieroglyphs in the 5th century BC, which depict "simple glass meniscal lenses".
📜 The written record of magnification also dates back to the 1st century AD, when Seneca the Younger, a tutor of Emperor Nero of Rome, wrote: "Letters, however small and indistinct, are seen enlarged and more clearly through a globe or glass filled with water". Nero is also said to have watched the gladiatorial games using an emerald as a corrective lens ⬆️.
👓 According to researchers, spectacles were invented more than 1000 years ago in ancient China and were in widespread consumer use in by the Chinese Imperial family, aristocrats and rich civilians.
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🔎 Scientists suppose that the first vision aid, called a reading stone, was invented around 1000 AD. The reading stone was a glass sphere that was laid on top of the reading material to magnify the letters.
🔎 One of the earliest historical reference to magnification dates back to ancient Egyptian hieroglyphs in the 5th century BC, which depict "simple glass meniscal lenses".
📜 The written record of magnification also dates back to the 1st century AD, when Seneca the Younger, a tutor of Emperor Nero of Rome, wrote: "Letters, however small and indistinct, are seen enlarged and more clearly through a globe or glass filled with water". Nero is also said to have watched the gladiatorial games using an emerald as a corrective lens ⬆️.
👓 According to researchers, spectacles were invented more than 1000 years ago in ancient China and were in widespread consumer use in by the Chinese Imperial family, aristocrats and rich civilians.
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How did the first wearable eyeglasses look like?
🤓 Most historians believe that the first form of eyeglasses was produced in Italy by monks or craftsmen around 1285-1289. These magnifying lenses for reading were shaped like two small magnifying glasses and set into bone, metal, or leather mountings that could be balanced on the bridge of nose.
🤓 The first known artistic representation of the use of eyeglasses was Tommaso da Modena's painting in 1352, depicting monks reading and writing manuscripts ⬆️. One monk uses a magnifying glass, but another wears glasses perched on his nose ⬆️.
🤓 Later, the first eyeglass frame temples were made by Spanish craftsmen in 1600s. They affixed ribbons of silk or strings to the frame and looped them over the user's ears.
🤓 The modern style of eyeglasses frame, which could be placed over the ears and nose, was invented in the 18th century in England. These early eyeglasses had glass lenses set into heavy frames of wood, lead or copper.
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🤓 Most historians believe that the first form of eyeglasses was produced in Italy by monks or craftsmen around 1285-1289. These magnifying lenses for reading were shaped like two small magnifying glasses and set into bone, metal, or leather mountings that could be balanced on the bridge of nose.
🤓 The first known artistic representation of the use of eyeglasses was Tommaso da Modena's painting in 1352, depicting monks reading and writing manuscripts ⬆️. One monk uses a magnifying glass, but another wears glasses perched on his nose ⬆️.
🤓 Later, the first eyeglass frame temples were made by Spanish craftsmen in 1600s. They affixed ribbons of silk or strings to the frame and looped them over the user's ears.
🤓 The modern style of eyeglasses frame, which could be placed over the ears and nose, was invented in the 18th century in England. These early eyeglasses had glass lenses set into heavy frames of wood, lead or copper.
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Who invented bifocals?
The first eyeglasses could only be used to rectify hyperopia or presbyopia, the eyeglasses for myopia appeared later. But there had been no single solution to help those who suffered from both types of vision impairments until 1784.
American polymath Benjamin Franklin is credited for inventing bifocals in 1784. He created them because he was tired of switching eyeglasses for far and near. Therefore, he combined the two lenses by cutting them and then combining the segments into one glass with a sharp switch between the upper and lower lenses.
In the 19th century, Louis de Wecker, a French ophthalmologist, helped to improve the original model by fusing the upper and lower sections.
Peter Williams, who invented trifocal lenses, is known for coining the term “bifocals” in 1824, although he credited Benjamin Franklin for the invention.
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The first eyeglasses could only be used to rectify hyperopia or presbyopia, the eyeglasses for myopia appeared later. But there had been no single solution to help those who suffered from both types of vision impairments until 1784.
American polymath Benjamin Franklin is credited for inventing bifocals in 1784. He created them because he was tired of switching eyeglasses for far and near. Therefore, he combined the two lenses by cutting them and then combining the segments into one glass with a sharp switch between the upper and lower lenses.
In the 19th century, Louis de Wecker, a French ophthalmologist, helped to improve the original model by fusing the upper and lower sections.
Peter Williams, who invented trifocal lenses, is known for coining the term “bifocals” in 1824, although he credited Benjamin Franklin for the invention.
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How progressive lenses were invented ?
The first patent for a design of progressive addition lenses (PAL) was obtained by Owen Aves in England in 1907. However, because of the limitations in manufacturing in those times, he was never able to produce and commercialize such lenses.
In the first half of the 20th century some other designs for progressive lens were patented but never successfully commercialized.
👓 ❗️The first progressive with a modern design was patented by Bernard Maitenaz ⬆️ of France, in 1953.
The progressive lens has been evolving since then, with the help of manufacturers to improve usability and distortion-free viewing.
ℹ️ Progressive lenses are a giant leap in lens technology since they allow the wearer the ability to see distance, intermediate, and near fields all in one set of eyewear. This is especially helpful for viewing digital devices since they reside in the intermediate range, which distance and bifocal eyeglasses cannot reach ⬆️.
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The first patent for a design of progressive addition lenses (PAL) was obtained by Owen Aves in England in 1907. However, because of the limitations in manufacturing in those times, he was never able to produce and commercialize such lenses.
In the first half of the 20th century some other designs for progressive lens were patented but never successfully commercialized.
👓 ❗️The first progressive with a modern design was patented by Bernard Maitenaz ⬆️ of France, in 1953.
The progressive lens has been evolving since then, with the help of manufacturers to improve usability and distortion-free viewing.
ℹ️ Progressive lenses are a giant leap in lens technology since they allow the wearer the ability to see distance, intermediate, and near fields all in one set of eyewear. This is especially helpful for viewing digital devices since they reside in the intermediate range, which distance and bifocal eyeglasses cannot reach ⬆️.
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What is a brief history of sunglasses?
😎 The first sunglasses were invented sometime in 12th century China. They were a crude slab of smoked quartz that was made to block out the light from the sun. The frames were roughly shaped frame to hold them against the user's face.
😎 Around 1430 vision-correcting eyeglasses were darkened and they were introduced into Italy via the Chinese.
😎 In the 18th century, an English optician James Ayscough began experimenting with tinted lenses in spectacles but not to protect from the sun but to improve vision for those with poor or failing eye sight. He believed that by changing the color of the lenses to a blue/green tint, he could correct specific vision impairments.
😎 The modern-type sunglasses appeared in the 20th century. In 1929, a US businessman Sam Foster, put sunglasses into mass production in America.
😎 Since 1970s well-known fashion designers and movie stars escalated the sunglass craze with their brand-name lines.
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😎 The first sunglasses were invented sometime in 12th century China. They were a crude slab of smoked quartz that was made to block out the light from the sun. The frames were roughly shaped frame to hold them against the user's face.
😎 Around 1430 vision-correcting eyeglasses were darkened and they were introduced into Italy via the Chinese.
😎 In the 18th century, an English optician James Ayscough began experimenting with tinted lenses in spectacles but not to protect from the sun but to improve vision for those with poor or failing eye sight. He believed that by changing the color of the lenses to a blue/green tint, he could correct specific vision impairments.
😎 The modern-type sunglasses appeared in the 20th century. In 1929, a US businessman Sam Foster, put sunglasses into mass production in America.
😎 Since 1970s well-known fashion designers and movie stars escalated the sunglass craze with their brand-name lines.
Subscribe- t.me/askmenow
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What is a lens and its types?
ℹ️ A lens is a piece of transparent material that is shaped to bend light rays in a specific way as they pass through it, whether that means causing the rays to converge to or diverge from a specific point.
The word “lens” derives from the Latin word “lentil,” owing to the shape similarities between a converging lens and a legume.
The 2️⃣ types of lenses are:
📍concave lenses with following features
🔎The light is spread out by a diverging lens.
🔎Thinner in the centre than at the edges.
🔎The image is on one side of the lens, while the object is on the other.
🔎The focal length is positive.
🔎The image will be erect, virtual, and diminished.
and
📍convex lenses with following features
🔍The refracted rays are converged by a converging lens.
🔍Thicker in the centre than at the edges.
🔍The object and the image are both on the same side of the lens.
🔍The focal length is negative.
🔍The resultant image will be both real and inverted.
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ℹ️ A lens is a piece of transparent material that is shaped to bend light rays in a specific way as they pass through it, whether that means causing the rays to converge to or diverge from a specific point.
The word “lens” derives from the Latin word “lentil,” owing to the shape similarities between a converging lens and a legume.
The 2️⃣ types of lenses are:
📍concave lenses with following features
🔎The light is spread out by a diverging lens.
🔎Thinner in the centre than at the edges.
🔎The image is on one side of the lens, while the object is on the other.
🔎The focal length is positive.
🔎The image will be erect, virtual, and diminished.
and
📍convex lenses with following features
🔍The refracted rays are converged by a converging lens.
🔍Thicker in the centre than at the edges.
🔍The object and the image are both on the same side of the lens.
🔍The focal length is negative.
🔍The resultant image will be both real and inverted.
Subscribe- t.me/askmenow
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Ask Me
What is a lens and its types? ℹ️ A lens is a piece of transparent material that is shaped to bend light rays in a specific way as they pass through it, whether that means causing the rays to converge to or diverge from a specific point. The word “lens” derives…
How do we use lenses?
Concave Lens is used:
✔️ to correct myopia eye defects
✔️ to make spectacles
✔️ in peepholes in hotel room doors.
✔️ in the construction of certain types of telescopes.
Convex Lens is used:
✔️ to correct hypermetropia eye defects
✔️ in cameras and digital cameras as optical devices for producing a reduced, true, and inverted image on film.
✔️ in microscopes and telescopes
✔️ to produce a magnified image of an object.
Subtypes of convex lens are:
📌 A bi-convex lens is a basic lens that consists of two convex surfaces in a spherical form with the same radius of curvature.
📌 Plano-convex lenses are positive focal length elements that have one spherical surface and one flat surface
📌 ConConvex lenses are also known as converging lenses since the rays converge after falling on the convex lens.
Subtypes of concave lenses are:
📌 A bi-concave lens have two inward curved surfaces. These lenses have a negative focal length.
📌 A plano-concave lens is an optical lens with one concave surface and one flat surface. It has a negative focal length and can be used for light projection, beam expansion, or to increase the focal length of an optical system.
📌 A concavo-convex lens is a converging lens. This is because it is thicker in the middle and thinner at the edges allowing it to converge all the light that is incident on it.
ℹ️‼️👀 The lens of our eyes is also convex. The inverted image of the item on the retina is formed by the eye lens.
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Concave Lens is used:
✔️ to correct myopia eye defects
✔️ to make spectacles
✔️ in peepholes in hotel room doors.
✔️ in the construction of certain types of telescopes.
Convex Lens is used:
✔️ to correct hypermetropia eye defects
✔️ in cameras and digital cameras as optical devices for producing a reduced, true, and inverted image on film.
✔️ in microscopes and telescopes
✔️ to produce a magnified image of an object.
Subtypes of convex lens are:
📌 A bi-convex lens is a basic lens that consists of two convex surfaces in a spherical form with the same radius of curvature.
📌 Plano-convex lenses are positive focal length elements that have one spherical surface and one flat surface
📌 ConConvex lenses are also known as converging lenses since the rays converge after falling on the convex lens.
Subtypes of concave lenses are:
📌 A bi-concave lens have two inward curved surfaces. These lenses have a negative focal length.
📌 A plano-concave lens is an optical lens with one concave surface and one flat surface. It has a negative focal length and can be used for light projection, beam expansion, or to increase the focal length of an optical system.
📌 A concavo-convex lens is a converging lens. This is because it is thicker in the middle and thinner at the edges allowing it to converge all the light that is incident on it.
ℹ️‼️👀 The lens of our eyes is also convex. The inverted image of the item on the retina is formed by the eye lens.
Subscribe- t.me/askmenow
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Ask Me
What is a lens and its types?
ℹ️ A lens is a piece of transparent material that is shaped to bend light rays in a specific way as they pass through it, whether that means causing the rays to converge to or diverge from a specific point.
The word “lens”…
ℹ️ A lens is a piece of transparent material that is shaped to bend light rays in a specific way as they pass through it, whether that means causing the rays to converge to or diverge from a specific point.
The word “lens”…
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What is a skyscraper?
🏙 Currently, a skyscraper refers to a tall habitable building with iron or steel frameworks over 100 m.
🌇 The first modern skyscraper was created in 1885—the 10-story Home Insurance Building in Chicago ⬆️.
📌 Before the word skyscraper described enormous buildings, it was used to describe anything that “stood out”, was tall - a tall man, a high-standing horse, a sky-sail, etc.
📌 Pointed out by skyscraper researchers, the Italian word ‘grattacielo’ means scraping the sky. It was in use since the early 13th century, and described a tall man.
📌 The word scraper dates back to the Old Norse word ‘skrapa’, which means to erase. Today, it means to use a tool to apply pressure to something. A skyscraper essentially erases the sky by sticking out and blocking it.
📌 Sources for the first usage of the word skyscraper are unclear. One of the oldest confirmed references in print was in American newspapers in the late 19th.
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🏙 Currently, a skyscraper refers to a tall habitable building with iron or steel frameworks over 100 m.
🌇 The first modern skyscraper was created in 1885—the 10-story Home Insurance Building in Chicago ⬆️.
📌 Before the word skyscraper described enormous buildings, it was used to describe anything that “stood out”, was tall - a tall man, a high-standing horse, a sky-sail, etc.
📌 Pointed out by skyscraper researchers, the Italian word ‘grattacielo’ means scraping the sky. It was in use since the early 13th century, and described a tall man.
📌 The word scraper dates back to the Old Norse word ‘skrapa’, which means to erase. Today, it means to use a tool to apply pressure to something. A skyscraper essentially erases the sky by sticking out and blocking it.
📌 Sources for the first usage of the word skyscraper are unclear. One of the oldest confirmed references in print was in American newspapers in the late 19th.
Subscribe- t.me/askmenow
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What is Bessemer Process and how it enabled the construction of skyscrapers?
☑️Bessemer process is a process of making steel from pig iron by burning out impurities (as carbon) by means of a blast of air forced through the hot liquid metal.
☑️It was the first inexpensive industrial process that allowed for the mass production of steel.
☑️This term bears its name from Henry Bessemer (1813-1898), an English inventor and engineer, devoted to metallurgy ⬆️.
☑️Though named after Bessemer, before it was commercialized, this process evolved from the contributions of many investigators, eg an American, William Kelly, who had also been working on a similar process for making steel.
🔘In any case, this breakthrough opened the door for builders to start making taller and taller structures.
ℹ️Modern steel is still made using technology based on Bessemer process.
ℹ️Taller buildings were also made possible through the invention of the electric elevator and lighting.
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☑️Bessemer process is a process of making steel from pig iron by burning out impurities (as carbon) by means of a blast of air forced through the hot liquid metal.
☑️It was the first inexpensive industrial process that allowed for the mass production of steel.
☑️This term bears its name from Henry Bessemer (1813-1898), an English inventor and engineer, devoted to metallurgy ⬆️.
☑️Though named after Bessemer, before it was commercialized, this process evolved from the contributions of many investigators, eg an American, William Kelly, who had also been working on a similar process for making steel.
🔘In any case, this breakthrough opened the door for builders to start making taller and taller structures.
ℹ️Modern steel is still made using technology based on Bessemer process.
ℹ️Taller buildings were also made possible through the invention of the electric elevator and lighting.
Subscribe- t.me/askmenow
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Who is known as the inventor of skyscrapers?
While “the Bessemer process” kept Bessemer’s name well-known, lesser-known today is the man who employed that process to create the first skyscraper and is often considered as the inventor of modern skyscrapers and construction.
It’s George A. Fuller (1851-1900)⬆️, an American architect.
Throughout the 19th century, construction techniques had called for outside walls to carry the load of a building’s weight.
Fuller, however, had a different idea. He realized that buildings could bear more weight—and therefore soar higher—if he used Bessemer steel beams to give buildings a load-bearing skeleton on the inside of the building.
In 1889, Fuller erected the Tacoma Building⬆️, a successor to the Home Insurance Building that became the first structure ever built where the outside walls did not carry the weight of the building.
Fuller developed a technique for creating steel cages that would be used in subsequent skyscrapers.
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While “the Bessemer process” kept Bessemer’s name well-known, lesser-known today is the man who employed that process to create the first skyscraper and is often considered as the inventor of modern skyscrapers and construction.
It’s George A. Fuller (1851-1900)⬆️, an American architect.
Throughout the 19th century, construction techniques had called for outside walls to carry the load of a building’s weight.
Fuller, however, had a different idea. He realized that buildings could bear more weight—and therefore soar higher—if he used Bessemer steel beams to give buildings a load-bearing skeleton on the inside of the building.
In 1889, Fuller erected the Tacoma Building⬆️, a successor to the Home Insurance Building that became the first structure ever built where the outside walls did not carry the weight of the building.
Fuller developed a technique for creating steel cages that would be used in subsequent skyscrapers.
Subscribe- t.me/askmenow
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What is the tallest building in the world?
🌇🥇🇦🇪 At an incredible height of 828 meters (2,717 feet), Burj Khalifa in Dubai, the United Arab Emirates, is the tallest recorded building in the world.
🔝It’s three times as tall as the Eiffel Tower.
🔝It has hotels, residential apartments and shopping malls that cover 2km2. Upon its completion in 2010, it broke several records, including the world's highest restaurant and nightclub. It also has the most number of floors (163) of any building ever constructed and the tallest elevator shaft in the world.
🔝It also has over 24,000 windows.
🔝The structure is built using reinforced concrete, aluminium and steel. It took more than 110,000 tons of concrete, 55,000 tons of steel rebar, and 22 million man-hours to complete the building. The total weight of aluminum used on the Burj Khalifa is equivalent to that of five A380 aircraft.
🔝The tip of the spire of the Burj Khalifa can be seen from up to 95 kilometers away.
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🌇🥇🇦🇪 At an incredible height of 828 meters (2,717 feet), Burj Khalifa in Dubai, the United Arab Emirates, is the tallest recorded building in the world.
🔝It’s three times as tall as the Eiffel Tower.
🔝It has hotels, residential apartments and shopping malls that cover 2km2. Upon its completion in 2010, it broke several records, including the world's highest restaurant and nightclub. It also has the most number of floors (163) of any building ever constructed and the tallest elevator shaft in the world.
🔝It also has over 24,000 windows.
🔝The structure is built using reinforced concrete, aluminium and steel. It took more than 110,000 tons of concrete, 55,000 tons of steel rebar, and 22 million man-hours to complete the building. The total weight of aluminum used on the Burj Khalifa is equivalent to that of five A380 aircraft.
🔝The tip of the spire of the Burj Khalifa can be seen from up to 95 kilometers away.
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What buildings are also in the world’s top-3 of the tallest constructs?
🏙🥈🇲🇾 The almost-completed Merdeka 118 ⬆️ is the second tallest building in the world, and the tallest building in South East Asia.
It towers 679 meters (2,220 feet) into the sky, overlooking the city of Kuala Lumpur in Malaysia.
The name Merdeka means Independence Day in Malaysian, while it will have 118 floors in total and is set to officially open in 2023.
🌆🥉🇨🇳 Set in Shanghai, China, Shanghai Tower ⬆️ is now the third tallest building in the world, measuring 632 meters (2,073 feet).
Completed in 2015, the impressive structure took nearly 20 years to complete after several funding issues arose during its construction.
The tower has one of the world’s fastest elevators, which travels at 20.5 meters per second, whizzing visitors up to the top of the building’s incredible 128 floors.
While Burj Khalifa is the tallest construct in the world, Shanghai Tower has the biggest number of usable floors.
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🏙🥈🇲🇾 The almost-completed Merdeka 118 ⬆️ is the second tallest building in the world, and the tallest building in South East Asia.
It towers 679 meters (2,220 feet) into the sky, overlooking the city of Kuala Lumpur in Malaysia.
The name Merdeka means Independence Day in Malaysian, while it will have 118 floors in total and is set to officially open in 2023.
🌆🥉🇨🇳 Set in Shanghai, China, Shanghai Tower ⬆️ is now the third tallest building in the world, measuring 632 meters (2,073 feet).
Completed in 2015, the impressive structure took nearly 20 years to complete after several funding issues arose during its construction.
The tower has one of the world’s fastest elevators, which travels at 20.5 meters per second, whizzing visitors up to the top of the building’s incredible 128 floors.
While Burj Khalifa is the tallest construct in the world, Shanghai Tower has the biggest number of usable floors.
Subscribe- t.me/askmenow
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