Eye Glasses in History

INTRODUCTION

Glasses - also called eyeglasses (formal) , spectacles, or specs (informal) - are frames Bearing lenses worn in front of the eyes, normally  for vision correction or eye Protection. Safety glasses are a kind of eye protection against flying debris or against Visible and near visible light or radiation.

Sunglasses allow better vision in bright Daylight, and may protect against damage from high levels of ultraviolet light. Other Types of glasses may be used for viewing visual information (such as stereoscopy) or Simply just for aesthetic or fashion values.

The word lens comes from the Latin name of the lentil , because a double-convex Lens is lentil-shaped. The genus of  the lentil plant is lens .and the most commonly Eaten species is lens culinaris. The lentil plant also gives its name to a geometric figure.

History of eyeglasses

Precursors

-Lenses in ancient Egypt

The earliest historical reference to magnification dates back to ancient

Egyptian hieroglyphs in the 5th century BC, which depict “simple glass

Meniscal lenses”. 

-Lenses in ancient Greece

The earliest written records of lenses data to Ancient Greece, with

Aristophanes’ play The Clouds (424 BC) mentioning a burning-glass

(a biconvex lens used to focus the sun’s rays to produce fire). 

-Lenses in ancient Roman

The earliest written record of magnification dates back to the 1 st centuries 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 (reigned 54 – 68 AD) is also said to have watched the gladiatorial games using an emerald as a corrective lens. 

          

Figure 1: Emerald Ring                                   Figure 2: Emerald % 2520 Clarity.

Figure 3: Emerald % 255C Gallery                  Figure 4: Emerald stone

                 

                      

Figure 5: Crude Emerald.                                  Figure 6: Emerald Marine

                                             

                                                   Figure 7: Emerald 300X300

- Lenses in the 9th century

Corrective lenses were said to be used by Abbas Ibn Firnas in the 9^th  century,  who had devised a way to produce very clear glass. These glasses could be shaped and polished into round rocks used for viewing and were known as reading stones.

Abbas Ibn Firnas (810 – 887 A.D.),also known as Abbas Qasim Ibn Firnas, Was a muslim Berber polymath: an inventor,  engineer, aviator,  physician,Arabic poet,and Andalusian musician. He was born in Izn-Rand Onda, Al-Andalus (today’s Ronda,Spain),and lived in the Emirate of Cordoba.He is known for an early attempt at aviation. 

Ibn Firnas designed a water clock called Al-Maqata,devised a means of manufacturing colorless glass, he invented various glass planispheres, Made corrective lenses(“reading stones”) , developed a chain of rings that could be used to simulate the motions of the planets and stars, and developed a process for cutting rock crystal that allowed Spain to cease exporting quartz to Egypt to be cut. 

Figure 8: Abbas Ibn Firnas, reading stone.

-Lenses in the 10th century

Ibn Sahl used what is now known as Snell’s law to calculate the shape of lenses. Ibn Sahl (c.940-1000)  was a Muslim Persian mathematician, Physicist and optics engineer of the Islamic Golden Age associated with The Abbasid court of Baghdad.Ibn Sahl’s 984 treatise On Burning Mirror and Lenses sets out his understanding of how curved mirrors and lenses bend and focus light. Ibn Sahl is credited with first discovering the law of refraction, usually called Snell’s Law. He used the law of refraction to derive lens shapes that focus light with no geometric aberration , known as anaclastic lenses.

                         

                                                Figure 9:  Ibn Sahl (Snell,s law).          

  

                                    Figure10:  Ibn Sahl,s work on refraction and optics

-Lenses in the 11th century

Widespread use of lenses did not occur until the use of reading stones in the 11 th century and the invention of spectacles, probably in Italy in the 1280s. Scholars have noted that spectacles were invented not long after the translation of Ibn al-Haytham’s  Book of Optics into Latin, but it is not clear what role,if any,the optical theory of the time played in the discovery.Ibn Sahl’s treatise was used by Ibn al-Haitham.

Abu Ali  al-Hasan  ibn al-Hasan  ibn al-Haytham(965 in Basra – c.1040 in cairo)  was a Persian  or Arab scientist and polymath.  He made significant contributions to the principles of optics, as well as to physics, anatomy, astronomy, engineering, mathematics, medicine,ophthalmology, philosophy, psychology, visual perception, and to science in general with his early application of the scientific method. He is sometimes called al-Basri, after his birthplace in the city of Basra.   He was also nicknamed Ptolemaeus Secundus (“Ptolemy the Second”) or simply “The Physicist” in medieval Europe. Alhazen wrote insightful comm -entaries on works by Aristotle, Ptolemy, and the Greek mathematician Euclid. 

Born circa 965, in Basra, Iraq and part of Buyid Persia at that time,  he lived mainly in Cairo, Egypt, dying there at age 76.   Over-confident about practical application of his mathematical knowledge, he assumed that he could regular the floods of the Nile. 

             Figure 11: Ibn Al-Haytham,s anatomy of the eye        

        

                                        Figure 12:Eye Diagram Ibn Al-Haytham

Figure 13: Optics (dated 1083):  Ibn al-Haytham's Optics, written in Eqypt in the first half of the 11th Century, represented a theory of vision that went beyond Galen, Euclid and Ptolemy. This diagram of the two eyes seen from above, shows the principal tunics and humours and the optic nerves connecting the eyeballs to the brain.

    

-Lenses in the 12th century

Sunglasses, in the form of flat panes of smoky quartz, protected the eyes from glare and were used in China in the 12th century or possibly earlier. Similarly, the Inuit have used snow goggles for eye protection. However, they did not offer any corrective benefits and the use by historians of the term "sunglasses" is anachronistic before the twentieth century.

                                       Figure 14: Smoky Quartz Gemstone.  

                           Figure 15: Smoky Quartz, Large loose  – 800X566.

                                       Figure 16: Smoky Quartz – 336X330.   

                                         Figure 17: Natural Smoky Quartz

 -Lenses in the 13th century

Englishman Robert Grosseteste's treatise De iride ("On the Rainbow"), written between 1220 and 1235, mentions using optics to "read the smallest letters at incredible distances". A few years later, Roger Bacon is also known to have written on the magnifying properties of lenses in 1262. Reportedly, spectacles were in use in China by the rich and elderly at the time of Marco Polo's arrival in 1270 or 1271, although the Chinese credit their invention to Arabia in the 11th century.

Invention of eyeglasses

Many theories abound for who should be credited for the invention of traditional eyeglasses. Despite evidence of spectacles in China in 1270, and Chinese claims of themselves importing spectacle technology from the Middle East in the 11th century, some people theorise that spectacles were first invented between 1280 and 1300 in Italy. Some also theorise that the first European inventor of spectacles was Salvino D'Armate.

In 1676, Francesco Redi, a professor of medicine at the University of Pisa, wrote that he possessed a 1289 manuscript whose author complains that he would be unable to read or write were it not for the recent invention of glasses. He also produced a record of a sermon given in 1305, in which the speaker, a Dominican friar named Fra Giordano da Rivalto, remarked that glasses had been invented less than twenty years previously, and that he had met the inventor. Based on this evidence, Redi credited another Dominican friar, Fra Alessandro da Spina of Pisa, with the re-invention of glasses after their original inventor kept them a secret, a claim contained in da Spina's obituary record However, Spina most likely learned to make spectacles after seeing them made by another individual, a talent for which he was known at the time.

Another potential inventor is Salvino D'Armate, who is credited with inventing the first wearable eye glasses on 16 September 1284 in Italy. In a 1684 history of Florence, Leopoldo del Migliore wrote that the church of Santa Maria Maggiore contained a memorial honoring D'Armati with the inscription: Here lies Salvino degl' Armati, son of Armato of Florence, inventor of eyeglasses. May God forgive his sins. A.D. 1317. The church has been rebuilt several times since the 13th century, however, and this tomb no longer exists, so the claim cannot be verified. Seated apostle holding lenses in position for reading. Detail from Death of the Virgin, by the Master of Heiligenkreuz, ca. 1400–30 (Getty Center).

The earliest pictorial evidence for the use of eyeglasses is Tommaso da Modena's 1352 portrait of the cardinal Hugh de Provence reading in a scriptorium. Another early example would be a depiction of eyeglasses found north of the Alps in an altarpiece of the church of Bad Wildungen, Germany, in 1403. 

These early spectacles had convex lenses that could correct both hyperopia (farsightedness), and the presbyopia that commonly develops as a symptom of aging. Nicholas of Cusa is believed to have discovered the benefits of concave lens in the treatment of myopia (nearsightedness). However, it was not until 1604 that Johannes Kepler published in his treatise on optics and astronomy, the first correct explanation as to why convex and concave lenses could correct presbyopia and myopia.

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