Why were sunglasses invented?

Sunglasses were originally invented by the Chinese in 12^th century and were worn by judges in courts of justice so that they could hide their eye expressions and emotions while questioning the victims. The lenses used were actually smoky quartz. Since then, sunglasses have come a long way.
A man named James Ayscough, experimented with tinting of lenses in the 18th century. He did not seek sunglasses as protecting your eyes from the rays of the sun, but for the correction of vision impairments.
Sunglasses were produced commercial only in the year 1929 by Sam Foster in USA. He found that the visitors at the beaches of Atlantic City were his first set of customers. The concept of Polaroid filter and the polarized sunglasses was introduced by Edwin H Land in 1936.
The 1960s saw the sunglasses being popular among people for the purpose of fashion. And the popularity has been increasing ever since. As on date, there are over a hundred brands which sell premium sunglasses. A popular brand called Oakley has launched sunglasses with a digital music player embedded in it.
Sunglasses have surely traveled a long way!
image courtesy: coolhunting.com