Before the invention of glasses, people’s life was restrained by the eyesight. For example, hunters’ far sight is more important than their short sight. Handicraftsmen who often use short sight have to put an end to their career around forty-five and fifty years old because they can’t see near things. The earliest lens is convex mirror like hyacinth bean. This can be dated back to the tenth century. As the invention of typographic and the spread of pulverization, the increasing demand for good eyesight accelerates the development of glasses.
From the thirteenth century, people began to use glass-instilled lenses to correct eyesight. Lens is made by dropping dissolved glass into mould. The earliest record about correcting eyesight is written by Roger Bacon in 1268. He said that if you got the convexity of crystal near your eyes, the letters became bigger and clearer.
Since Johan Gutenberg invented the printer, more and more people need to correct eyesight. Soon people found out that the concave could help people see far objects. From that time, lenses were divided according to different degrees instead of ages.
The earliest glasses were fastened in front of eyes with a rope. It is very inconvenient and not safe. In the eighteenth century, the Chinese invented “ear support”. Then, after a time, the English man Edward Scanlett made a glasses frame, which was the rudiment of modern ear’s glasses frames. This made us more comfortable when we wore glasses.
The nineteenth century is an important period of the development of glasses and lenses. During this period, glasses invention made a great progress. Fuller invented column lens to correct eyesight. Snellen invented criteria eyesight chart to measure eyesight in 1860. Lenses we use now were designed in about 1890. Producers are searching for new products constantly to satisfy different demands of consumers. For instance, the mass production of coloring lenses like sunglasses started in the early time of the twentieth century. This kind of lenses can be used to improve eyesight and reduce the radiation of infrared rays.
Sunglasses are very popular now. In this summer, you may choose one pair for yourself from glassesshop.com to protect your eyes. I think we are lucky because we were born in such a good time. We can always see things clearly due to glasses. I believe that glasses will develop more and have more functions so that our eyes can be protected better.