Understanding Vision

The history of glasses

From their origins as "reading stones" to lifestyle accessories

12 November 2021

According to experts, glasses are the fifth most important invention since mankind discovered fire and invented the wheel. The reason: for the first time in human history, millions of people were able to enjoy good vision in spite of problems with their vision. Today we take this for granted, but for centuries there was simply no solution for those suffering from a visual impairment – glasses still had to be invented. It took a long time to develop the modern glasses we know today. This processes required a lot of experimentation, and many different types of glasses came and went. BETTER VISION recounts the history of glasses – from their beginnings as "reading stones" to their transformation into sought-after lifestyle and fashion accessories.

The invention of glasses is considered a crucial step forward in humanity's cultural history: suddenly, people suffering from visual impairments could not only play an active role in day-to-day life, but also study for longer, expand their knowledge and then pass it on to others. The great Roman orator Cicero (106-43 BCE) lamented how cumbersome it was to have slaves read texts aloud. Or take the special kind of visual device created by the emperor Nero (37-68 CE): he watched his beloved gladiator fights using a transparent green stone in the hope that the light would refresh his eyes. This belief persisted into the 19th century. "Sunglasses" from that period had green lenses and were also worn indoors. But when and where did the invention of a proper visual aid actually begin?

The world's first vision aid

The Arab scholar and astronomer Ibn al-Heitam (ca. 965-1040 CE) was the first to suggest that smoothed lenses might assist someone suffering from a visual impairment. However, his idea of using parts of a glass sphere for optical magnification was only put into practice many years later. His "Book of Optics" was translated into Latin in 1240 and found an attentive readership in many monastic communities. It was here that Ibn al-Heitam's ideas became reality: in the 13th century, Italian monks developed a semi-spherical lens made of rock crystal and quartz that, when placed on a piece of writing, magnified the letters! This "reading stone" was a true blessing for many older monks suffering from presbyopia and significantly improved their quality of life. During this period, the German word for glasses (Brille) started to come into use. The term is derived from beryll, the name of the rock crystal that was smoothed down to form the first lenses.

The birthplace of glasses

While reading stones helped people with day-to-day vision, these were still a long way from glasses as we know them today. That came with an invention created at the famed Murano glassworks in the 13th century. Murano, a small island to the north of Venice, was long considered a centre of glass manufacture. The artisans' glass-making expertise was not shared with outsiders: the formulas were top-secret, and the cristalleri or glassmakers were forbidden to leave the island. There was a time when anyone caught violating these rules could be put to death. During this period, the entire world looked to Italy because the white glass necessary for producing visual aids was only produced in the Murano glassworks.

At the end of the 13th century, the cristalleri succeeded in making a major breakthrough: for the first time, they ground two convex lenses, placed each of these in a wooden ring with a shaft and connected these with a rivet. And eureka: the first pair of glasses had been created! To be sure, this pair of "rivet glasses" did not feature any means of attaching them to the wearer's head. Nevertheless, it was the be-all-and-end-all in vision comfort. To improve their vision, the wearer just had to hold the "double glass" in front of their eyes. The invention was even immortalised in a building in the region. In 1352, Tomaso di Modena painted the frescoes in the chapter house of the Dominican monastery of San Nicolo in Treviso, including a reading glass and double-rivet glasses. Moreover, in spite of all the glassmakers' efforts, it was not possible to keep all the mysteries of glass manufacture a secret. To ensure Venice remained the market leader in the glass business, only those who adhered completely to the stipulations of the cristalleri were permitted to manufacture "eye glasses" after 1300. Over time, the rivet glasses also found their way to Germany: the oldest example was discovered in Wienhausen Abbey in the northern part of the country.

As the years passed, glass makers replaced the shaft of the rivet glasses with an arch, and the wooden frames with lead. The result marks another important step in the evolution of vision aids: glasses with temples that closely resembled those we know today. Increasingly diverse materials were used: beginning in the 16th century, leather, tortoise shell, horn, whalebone, iron, silver and bronze were processed. These were all materials that only the rich could afford.

Glasses today

The glasses we see and wear today ultimately emerged at the beginning of the 18th century. The greatest problem with visual aids was the fit: either they would keep sliding down the wearer's face or could only be kept in place with great difficulty and irritation. One benefit of "ear glasses" or "temple glasses" versus predecessor models was that they featured a nose bridge and temples for holding the glasses in place via the ear. A metal ring was often attached to the end of the temples for a more comfortable fit. The first examples of these glasses appeared in London and can be seen in a promotional brochure from the English optician Scarlett from 1728. People were also thinking about how to improve glasses in the United States. Did you know that in 1784 Benjamin Franklin created bifocal lenses, the predecessor to today's varifocal lenses? This is why bifocal lenses are still known as "Franklin glasses."

Modern "temple glasses" began to become widespread starting in 1850. Their basic design has largely gone unchanged over the past century and a half. However, wearer comfort has improved over time with better designed temples and more comfortable nose pads until they achieved anatomic perfection at the beginning of the 20th century.

At this point, the quality of glasses had reached a new apex – and yet ZEISS was still able to make crucial improvements to spectacle lenses. "You see a lot better with glasses than without" – that was the predominant opinion amongst the general population. But ZEISS asked an important question: is it possible to further optimise a spectacle wearer's vision by improving the lenses? Rather than focusing on products that would sell better, ZEISS began to develop spectacle lenses to support the eye across the entire field of view starting in 1908. The team headed by the famous optical scientist Moritz von Rohr (1868-1940) and the Swedish ophthalmologist and later Noble prize winner Allvar Gullstrand (1862-1930) devoted all its attention to spectacle lenses for cataracts patients because they had the greatest need for improved vision. Their research resulted in Punktal^®, the very first spectacle lenses with point-focal imagery and inciting an eye care revolution that took the world by storm in 1912. Punktal^® made it possible for the wearer to see clearly when looking through the peripheral areas of the lens. Prior to this invention, wearers had to turn their head so that the object was at the centre of the spectacle lens if they wanted to see it clearly. This achievement is still shaping the world of eye care today. Another success followed in 1935: with Perivist, ZEISS created the world's first frames fitted to accommodate the wearer that did not slide down. In other words: ZEISS produced the first modern pair of glasses. Previously, only round optical lenses could be used.

Learn more about the different types of spectacle lenses.

Glasses in all shapes and sizes

Vision aids of all shapes and sizes were developed in the wake of the reading stone. For example: the monocle was a popular accessory amongst well-to-do men and women in Germany and England starting in 1727. The lorgnette, a visual aid that you hold in front of your eyes with a handle, followed in 1780. The Nuremberg rimmed glasses, which people not-so-affectionately called "nose-crushers", also date from around this time. This was a sleek pair of frames consisting of a long, single piece of wire wrapped around the lenses. Although made of relatively simple materials, it was extremely popular into the 19th century. Then the fashion changed, and people opted for the prince-nez instead. The "star" amongst vision aids featured two lenses connected with a wire framed in rings that sat high on the root of the wearer's nose. Starting in 1841, no other design was so indicative of the affluent German bourgeoisie.

What glasses can do today

From precision varifocal lenses and special lenses for the digital world to driving glasses or spectacle lenses designed with contact lens wearers in mind: our goal to continually optimise people's vision has produced many innovative lens designs and solutions since the creation of Punktal^® lenses.