The UV protection in sunglasses is just one of several innovations from NASA's research in optics.

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Has anyone ever told you not to look directly at the sun because it would hurt your eyes? It's true that the sun puts off massive amounts of energy. Fortunately, the Earth's atmosphere reflects and scatters that solar energy before it reaches the planet's surface, protecting us from some of its harmful effects [source: Pidwirny]. If you're orbiting above Earth's protective atmosphere, though, you need more sophisticated technology to protect your eyes and skin from the sun.

When the National Aeronautics and Space Administration (NASA) prepared to send astronauts into space, eye protection and other optical considerations were essential components in developing its space helmets. Optics is the science of light, including how it's created, how to change and control it, and light-related phenomena like rainbows [source: Merriam-Webster]. Through its Technology Utilization Program (TUP), NASA has conducted optics research on space helmets that has made a substantial contribution to optics in many commercial products unrelated to space exploration [source: NASA].

In the 1980s, NASA researchers studied the harmful effects of ultraviolet light on the human eye. They found that ultraviolet light from the welding work that astronauts do caused inflammation of the cornea and long-term damage to the retina. To counter the effects of the UV light produced during welding, researchers developed a welding curtain to filter the light. The solution was inspired by the natural chemistry in the eyes of birds of prey, which allows them to spot targets over great distances [source: NASA].

The welding industry wasn't the only benefactor of this technology. If you're just walking outside in the sunlight, you're encountering the portion of the sun's ultraviolet (UV) light that isn't filtered through the Earth's atmosphere. Researchers have linked UV exposure in our eyes to the temporary discomforts caused by photokeratitis and the long-term effects of cataracts, which include possible blindness. To help protect your eyes, you can use sunglasses with UV protection. Eagle Eye Optics was established to use NASA-based technology in developing sunglasses with UV protection. Spurred by the increased awareness of UV's damaging effects (according to NASA's research), other industries found ways to add UV protection to other optical products, including eyeglasses and contact lenses [sources: NASA, AOA].

Next, let's look at some products that benefited from NASA's optical research and space helmet design.