Vintage AO Coverglass American Optical and similar items

The image shows a pair of vintage AO Coverglas American Optical welding goggles, likely from the 1950s, featuring green lenses and a cloth strap.(has some discoloration and tears). These goggles were designed to protect the eyes during welding or other industrial work, with the green lenses filtering out harmful light and the sturdy construction providing durability. The metal parts of the frames may show signs of oxidation, which can appear as a green residue due to the copper content in the metal alloy. The frames made out of bakelite and metal . American Optical has been a manufacturer of eyewear since 1833, and is known for its quality and durability. Green lenses in eyewear are often used to provide better contrast and color accuracy, making them suitable for various environments, including sunny and low-light conditions. Please see pictures for conditions. Also there is stamped on inside of the frames on both sides : AO COVERGLASS and there is a stamp on each glass there is circled welding symbol and letter M next to it .