Bacon and his glasses

Mid-thirteenth century, the British scholar Francis Bacon see a lot of people because of bad eyesight, can not see the text on the book, wanted to invent a tool to help people improve their eyesight. To this end, he wanted a lot of ways to do a lot of testing, but without success.
One day after the rain, Bacon came to the garden walk, see a lot of spider web dip raindrops, he found that looking through the raindrops leaves a lot of enlarged veins, even the leaves can be seen on the thin hair. He saw this phenomenon was very happy. Bacon immediately ran home, rummaging, and found a glass ball. But through the glass ball, reading the text, or blurred. He also found a diamond with a hammer, cut out a piece of the glass, took a look at this piece of glass close to the book, the text really magnified. Test is successful, Bacon ecstatic. Later, he also found a piece of wood, dug a round hole, put something piece of glass balls, and then the placement of a handle, easy to hand, so that people read the writing on the more convenient.
Later, through continuous improvement of such lenses has become is now wearing glasses. There is light vision correction myopia young and old used to wear reading glasses, and other various uses of glasses, people learn, work even more convenient. Bacon progress of human civilization has made a contribution.