Post by Rhonda on Jun 20, 2008 2:35:38 GMT -5
History of Spectacles
In the Middle Ages wearing spectacles signified knowledge
and learning. Painters of the time often included spectacles
when portraying famous persons even when depicting people
who lived before the known invention of spectacles. On
numerous paintings the religious teacher Sofronius Eusebius
Hieronymus (340 - 420 AD) is portrayed with a lion, a skull
and a pair of reading glasses. He is the patron saint of
spectacle makers.
***
It actually is true that eating carrots can help you see
better. Carrots contain Vitamin A, which feeds the chemicals
that the eye shafts and cones are made of. The shafts
capture black and white vision. The cones capture color
images.
***
Healthy eyes are so sensitive to light that a candle
burning in the dark can be detected a mile away. The human
eye can distinguish about 10 million different colors.
There currently is no machine that can achieve this
remarkable feat.
***
Roman tragedian Seneca is said to have read "all the books
in Rome" by peering through a glass globe of water. A
thousand years later, presbyopic monks used segments of
glass spheres that could be laid against reading material
to magnify the letters, basically a magnifying glass, called
a "reading stone." They based their invention on the
theories of the Arabic mathematician Alhazen (roughly 1000
AD). Yet, Greek philosopher Aristophanes (c. 448 BC-380 BC)
knew that glass could be used as a magnifying glass.
Nevertheless it was not until roughly 150 AD that Ptolemy
discovered the basic rules of light diffraction and wrote
extensively on the subject.
***
Venetian glass blowers, who had learned how to produce
glass for reading stones, later constructed lenses that
could be held in a frame in front of the eye instead of
directly on the reading material. It was intended for use
by one eye; the idea to frame two ground glasses using
wood or horn, making them into a single unit was born in
the 13th century.
***
In 1268 Roger Bacon made the first known scientific
commentary on lenses for vision correction. Salvino
D’Armate of Pisa and Alessandro Spina of Florence are often
credited with the invention of spectacles around 1284 but
there is no evidence to conclude this. The first mention of
actual glasses is found in a 1289 manuscript when a member
of the Popozo family wrote: "I am so debilitated by age
that without the glasses known as spectacles, I would no
longer be able to read or write." In 1306, a monk of Pisa
mentioned in a sermon: "It is not yet 20 years since the
art of making spectacles, one of the most useful arts on
earth, was discovered." But nobody mentioned the inventor.
***********************************************************
In the Middle Ages wearing spectacles signified knowledge
and learning. Painters of the time often included spectacles
when portraying famous persons even when depicting people
who lived before the known invention of spectacles. On
numerous paintings the religious teacher Sofronius Eusebius
Hieronymus (340 - 420 AD) is portrayed with a lion, a skull
and a pair of reading glasses. He is the patron saint of
spectacle makers.
***
It actually is true that eating carrots can help you see
better. Carrots contain Vitamin A, which feeds the chemicals
that the eye shafts and cones are made of. The shafts
capture black and white vision. The cones capture color
images.
***
Healthy eyes are so sensitive to light that a candle
burning in the dark can be detected a mile away. The human
eye can distinguish about 10 million different colors.
There currently is no machine that can achieve this
remarkable feat.
***
Roman tragedian Seneca is said to have read "all the books
in Rome" by peering through a glass globe of water. A
thousand years later, presbyopic monks used segments of
glass spheres that could be laid against reading material
to magnify the letters, basically a magnifying glass, called
a "reading stone." They based their invention on the
theories of the Arabic mathematician Alhazen (roughly 1000
AD). Yet, Greek philosopher Aristophanes (c. 448 BC-380 BC)
knew that glass could be used as a magnifying glass.
Nevertheless it was not until roughly 150 AD that Ptolemy
discovered the basic rules of light diffraction and wrote
extensively on the subject.
***
Venetian glass blowers, who had learned how to produce
glass for reading stones, later constructed lenses that
could be held in a frame in front of the eye instead of
directly on the reading material. It was intended for use
by one eye; the idea to frame two ground glasses using
wood or horn, making them into a single unit was born in
the 13th century.
***
In 1268 Roger Bacon made the first known scientific
commentary on lenses for vision correction. Salvino
D’Armate of Pisa and Alessandro Spina of Florence are often
credited with the invention of spectacles around 1284 but
there is no evidence to conclude this. The first mention of
actual glasses is found in a 1289 manuscript when a member
of the Popozo family wrote: "I am so debilitated by age
that without the glasses known as spectacles, I would no
longer be able to read or write." In 1306, a monk of Pisa
mentioned in a sermon: "It is not yet 20 years since the
art of making spectacles, one of the most useful arts on
earth, was discovered." But nobody mentioned the inventor.
***********************************************************