We've all known since we were kids that we shouldn't look directly at the sun. However, with the North American total eclipse coming on August 21, it's probably a good idea to revisit some safety measures when it comes to viewing eclipses.
Eclipses can be a wondrous thing. They don't happen very often, so it's hard to pass up the chance to see one in real life. If the moon had a perfectly circular orbit around Earth, we'd see an eclipse every month and it would be just like any other common natural phenomenon. Instead, the moon's orbit is tilted, making eclipses quite rare. At a certain point in time, the moon will pass right between the Earth and the sun, partially or totally blocking the sun from view on Earth.
Though a total eclipse blocks out the sun, it's still better not to risk looking directly at it without some sort of protection. Thus, it's best to prepare so we don't miss this rare occurrence.
Why isn't it safe to look at a total eclipse even though the moon is completely blocking the sun? Experts say that looking directly at even a small bit of light from the sun can damage your eyes. Looking directly at the sun can give rise to chemical reactions in our retinas. Our eyes can suffer from photochemical lesions and we can even go blind.
Fortunately, there are a couple of things you can use to safely view the North American total eclipse. One such equipment is a pinhole camera, though this is a more indirect way to view an eclipse. However, it's safer than looking at an eclipse with the naked eye. You can even make a pinhole camera at home.
You can also use eclipse glasses (also called “personal solar filters” or “solar-viewing glasses”), which will allow you to directly and safely view an eclipse. It's important to remember that regular sunglasses are in no way safe to use when you want to look directly at the sun, eclipse or no. Eclipse glasses have lenses with solar filters that are hundreds of thousands of times darker than the lenses of regular sunglasses. If you decide to go with eclipse glasses, make sure that they meet the current international standard, ISO 12312-2.
Be warned, though, that there are knock-offs of these glasses floating around on the market. If you've chosen to use eclipse glasses, you also need to make sure that they're genuine. This way, you won't be risking your sight for just a couple of minutes of an albeit wondrous natural phenomenon. According to the American Astronomical Society (AAS), vendors such as Daystar, Celestron, American Paper Optics, and Rainbow Symphony are reputable and sell glasses that meet the international standard.
Different retailers sell these glasses, and you can also borrow them if you so choose. Just make sure they meet the international standard and that the lenses have no scratches on them. You can look more into equipment such as these to make sure that your experience with viewing the North American total eclipse is a safe one.
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