If you want to find out when the sunglasses were invented, you'll see that they were already used in China in the 12th century or possibly even earlier. They were made of smoky quartz in those times and protected not only from the sunshine but from the sights of other people. Those who wear sunglasses leave almost no chance for anybody to read their emotions. Contemporary documents describe the use of such glasses by judges in Chinese courts to conceal their facial expressions while questioning witnesses.