#3 Scratch Resistant Lenses
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If you wear glasses, consider yourself lucky you live in a day where your lenses are virtually scratch proof. Back in the day, polished and ground glass was the preferred lenses to use in the eyeglass biz. In 1972, the regulations here in the US changed, all sunglasses and prescription lenses now had to be shatter-resistant. Plastic worked much better than glass for shatter proofing, but the lenses also were very prone to scratches. Fortunately, NASA was one of the earliest to the scene of scratch-resistant coatings for prescription and sunglass lenses. Along with Ames Research Centers coatings for astronaut helmet visors and plastic membranes, NASA developed sunlight-filtering lenses to enhance colors and add eye protection. Since then, these technologies can be found in welder’s safety masks, sunglasses, ski goggles, and prescription eyeglasses. 

Sources:
www.jpl.nasa.gov
www.nasa.gov
www.spacefoundation.org 
Image credit: iStock.com/Ersler

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