The first known sunglasses were used in ancient Rome, around 60 A.D., where the ruling elite used a primitive version of the modern sunglass to protect the eyes from the sun's glare. It is reported that the Emperor Nero used to watch gladiator events, which took place outdoors under the bright Roman sun, through sophisticated polished gems to reduce glare. The Emperor Nero may have been the original trendsetter of designer sunglasses for men. The ancient Roman sunglasses were simple eyepieces and did not block out UV rays, nor correct vision. In ancient China, around the 12th century, presiding judges used dark glasses to mask their facial expressions from witnesses and in public settings. The lenses were constructed from smoke-colored quartz lenses, which hid the judges' eyes from the public, while enabling them to see. Although this form of ancient eyewear, strictly speaking, was not used as a sunglass because it was not designed to shield the eyes from the sun, it is still considered a forefather of modern day designer sunglasses for men. Between the years 1400 and 1750, several developments took place that shaped the history of sunglasses. During the 1430s, Italian opticians discovered how to correct vision impairments with corrective lenses, and started offering prescription lenses. As more and more people started using eyeglasses, they were beginning to be considered as a practical, functional device rather than a vanity item for scholars or elites. The utility of eyeglasses was further bolstered during the early 1600s when the concave lens was invented. Another notable change, a simple and brilliant addition to early eyeglasses, came in 1730 when one Edward Scarlett came up with the idea of solid sidebars which could hold eyeglasses in front of the eyes, without slipping off. Up until then, eyeglasses had to held in place. The next installment of change in designer sunglasses for men came during the eighteenth century through the work of an enterprising optician by the name of James Ayscough. He believed that eyeglasses with green or blue tinted lenses could potentially correct some types of eyesight impairment. He experimented with colored lenses solely as a means of correcting vision problems, and not to protect the eyes from the sun. The sunglass as we know it today was introduced to the U.S. by Sam Foster in the late 1920s. This was the beginning of the Foster Grant saga. Foster's products were genuine sunglasses, in that they were designed to protect the eyes from the sun. Foster had stumbled upon a ready market, and the new product took off in leaps and bounds. Another significant technological advancement came in 1936, when the inventor of the Polaroid filter, Edwin Land, started employing his patented technology on sunglasses. Soon after, fashion-conscious elites and Hollywood heroes and starlets took to the sunglass phenomenon, and a new cultural icon was born in the form of designer sunglasses for men and women.