separate distance and presbyopic glasses

Prescription glasses continue to develop in the next few decades, especially the design of the glasses frame, and how to make them sitting comfortably in the nose. Frame made of leather, bone, ivory, tortoise shell and metal, simply supported or nose balance. The first frame weapons or the side of the early appearance of banded around the back of the ear. Instead of cycling, end top behind the ear China ribbons hanging down additional ceramic weight. The solid side finally arrived at was invented in 1730, by Edward Scarlett. Later, to make a great leap forward, when the lens is the famous Benjamin Franklin invented in 1780, the first double optical lens, known as "the Franklin separatist" double focus, so that people with presbyopia reading, also saw in the distance, without the need for separate distance and presbyopic glasses.
Sunglasses, as we know them today, by Sam Forster, 1929 was first introduced in the United States of america. First for the protection of human eye harmful rays of the sun is the sunglasses. He founded the Foster Grant company, in the city of the Atlantic, New Jersey, Beach Boardwalk and sales of the first for Foster Grant sunglasses. The first mass-produced sunglasses is this, and from this year, sunglasses really started to take off. When I say "take off", I mean, it is no exaggeration to say that, because in 1930, the Army Air Corps ask a company Bausch and Lomb (who still exist today) to produce a spectacle of hue, will effectively reduce the high altitude sun glare pilots. They developed a deep green color, light yellow absorption in the visible spectrum.
In 1936, Edwin land patent filters, Oakley Sunglasses. The different color to reduce reflection surface glare, such as water. Later in the same year, Ray-Ban Aviator Sunglasses design further Aviator style sunglasses, we know today, polarizing lens technology recently invented. The edge of the features of the framework at the edge of the cheek sagging a teardrop shape, give a all-round protection pilot whole eyes, who often look down, instrument panel for aircraft. Polarized lenses, reduce the glare of light reflected dashboard. Aviator sunglasses is free, but in 1937, the general public on the aviator style model, namely "ban" the light of the sun, Oakley Sunglasses.