If you use glasses since you were a kid, you probably remember how often your parents scolded you for breaking them. Whether it was in the park or in class, you’d get hit in the face by a ball or just tripped and come back home with a broken side piece. You probably didn’t notice it then, but lenses used to come out unscathed. Why? Once again, we owe it to space technology.
Long before space suits existed, when no one had ever travelled into space, the lenses in glasses were very easily broken, because they were made of… Bingo! Glass is the answer. However, when astronauts started exploring space, it became imperative to develop new materials that would resist the severity of that very hostile environment.
One of those newly found materials was used in space helmet visors. So far, glass had worked just fine, but it was not suitable for the high temperatures and pressure in space. A transparent, non-scratchable, unbreakable, resistant material was needed. Interestingly, after the new visors were developed, someone came up with the idea of using that very material in sunglasses. In space, however, the sun burns way harder than on the beach!