NASAAstronauts have seen some of the best views of any human in history.
From the surface of the moon to a crescent Earth, their eyes have experienced firsthand a grandeur that most of us will never witness.
But those breathtaking views come at a high price for many because in space, astronauts are exposed to higher levels of high-energy light, or radiation, compared to on Earth.
And sometimes that radiation strikes the lens and retina — the largest part of the eyeball. This has caused cataracts in over 3 dozen astronauts.
So in the 1980s, NASA scientists James Stephens and Charles Miller began looking into a preventative solution.
They came up with a special material “capable of absorbing, filtering, and scattering dangerous light,” and 10 years later, that material was commercialized and a company named Eagle Eyes Optics started making sunglasses with it.
Now, you can buy them for less than $80 – prices range from $39.95 to $79.95.
In 2010, the Space Foundation inducted this NASA technology into its Space Technology Hall of Fame. Here’s an example, provided by NASA, of what looking through an average pair of sunglasses looks like (left) compared to looking through a pair of Eagle Eyes’ sunglasses:
NASAThe coating uses the same technique that helps birds of prey see so well.
Eagles, for example, have tiny droplets of oil across the surface of their eyes, which work to filter out harmful radiation, like UV light. As a result, eagles have remarkably sharp eyesight, which they use to spot, track, and catch prey.
Stephens and Miller replicated the same process in their coating, which can not only eliminate 99.9% of harmful radiation but can also “enhance visual clarity,” according to NASA.
One of the benefits of polarizing sunglasses, like Eagle Eyes, is that they reduce glare, like in this example GIF (below) where StarReviews on YouTube uses Eagle Eyes to reduce glare on cars (StarReviews rated the Eagle Eyes a 5 out of 6 stars):There are other sunglasses that can reduce glare and eliminate UV light. What makes Eagle Eyes’ different is that they are the only sunglasses that use NASA-certified technology.
When you’re shopping for sunglasses, here are the basics in any good pair:
- The sunglasses eliminates at least 99% of all UV radiation. Cheap sunglasses generally block out some light, which opens your iris. This allows more light to enter your eye, and that means harmful UV if your sunglasses are not designed to block it.
- The sunglasses are polarized, which means they can reduce glare from reflected light off of a surface, like a car hood or snow.
- The sunglasses eliminate blue light. Some studies have shown that blue light, together with UV light, can harm the cornea and retina over time, causing cataracts.
Eagle Eyes’ sunglasses have all of the above. Other sunglass brands include:
- Oakley (who offer 99% protection against UV)
- Prada (who does not provide any of the above information on their site)
- and Persol (who says that their sunglasses are polarized and “anti-glare” treatment, but no information about UV elimination)
Article source: SAI http://feedproxy.google.com/~r/typepad/alleyinsider/silicon_alley_insider/~3/8Ys73xGRoIw/nasa-sunglasses-2015-9