How to safely view the total solar eclipse


By Brian Lada, Accuweather

Viewing the upcoming total solar eclipse on Aug. 21 does not only mean planning where to travel to see it, but also having the proper tools to view it safely.

Eclipse glasses feature a specially designed pair of solar filters, which allow people to safely view the sun and are a necessity for viewing an eclipse.

The only time that people do not need to wear these solar filters is during the brief period of time when the moon completely covers the face of the sun, also known as totality.

"You use these filters when any part of the bright sun is visible, but during totality when all of the bright sun's face is covered, you take them off and look at what is arguably one of the most spectacular sights in all of nature," said Rick Fienberg, press officer of the American Astronomical Society.

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States where you can see the total solar eclipse of 2017
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States where you can see the total solar eclipse of 2017

Salem's the first sizable U.S. city with a chance to catch the eclipse when it hits Oregon.

Source: NASA

The eclipse will hit residents in Idaho next, with an opportunity to see totality in Idaho Falls. In Boise? Drive north a bit for your chance at totality.

Source: NASA

The eclipse sweeps across most of Wyoming, with Casper perfectly placed along the center of the path -- which means the eclipse will last longer there than on the outer edges.

Source: NASA

In Montana, but don't want to leave the state to get your eclipse fix? Totality will be visible from a tiny sliver of the Southwest corner of the state, but it's probably easier to just drive all the way to Idaho or Wyoming instead.

Source: NASA

Plenty of Nebraskans will have the chance to catch totality -- as the moon's shadow passes from the northwest corner of the state to the southeast corner.

Source: NASA

Like Montana, the total eclipse path will scrape across the tiniest portion of Iowa, but again, your best bet will likely be to travel into a state to your south or west instead. 

Source: NASA

You can catch the total eclipse from Kansas too if you head up to the northeast corner.

Source: NASA

Folks in Kansas City will get to see the total eclipse in Missouri, along with those in Columbia as it heads southeast across the state. St. Louis residents might need to drive a bit to see the total show.

Source: NASA

Residents of southern Illinois will get a total eclipse treat too, but anyone north of Belleville will need to drive to catch the big sight.

Source: NASA

Most folks in southwest Kentucky will get a chance to see the moon's shadow too.

Source: NASA

The eclipse will sweep across a big swath of Tennessee next, hitting Nashville and sweeping between Knoxville and Chattanooga.

Source: NASA

The northeast corner of Georgia is in the eclipse's path too. 

Source: NASA

Only a handful of North Carolinians will be able to see the total eclipse from their homes, as it hits a tiny portion of the southwest corner of the state.

Source: NASA

Source: NASA

Check out the entire eclipse's path!

Source: NASA

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1. Why it is important to wear eclipse glasses, not sunglasses

Looking at the sun without specially made solar filters, even for a few seconds, can lead to long-term, irreversible eye damage.

"The reason that [eclipse glasses] are important is because the sun is so insanely bright that if you were to look at it for more than a fraction of a second, you would risk serious injury to your retinas," Fienberg said.

Some may think that dark sunglasses are just as good, but they do not offer nearly enough protection.

"Not only do [eclipse glasses] block 100,000 times more visible light than ordinary sunglasses, but they also block potentially harmful ultraviolet and infrared radiation, " Fienberg said.

2. Solar filters for cameras, telescopes and binoculars

Eclipse glasses are meant for people to wear to view the sun, but it is important not to pair them with binoculars, telescopes or a camera.

"You absolutely must never ever look at the sun with any kind of magnification without a special filter," Fienberg said.

Binoculars and telescopes focus sunlight, so using solar filters incorrectly with these object can lead to significant eye damage.

"The only filters that work with optics are filters that are made to go over the front and can be attached securely," Fienberg said.

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Solar filters for telescopes, binoculars and cameras are commonly sold by manufacturers, so those planning to use any of these items should purchase the filters ahead of time and test them out before the day of the eclipse.

Fienberg added that looking at the digital display screen of a camera or cell phone won't harm your eyes, but it may burn out the sensor in the camera.

3. Where to find eclipse glasses

People that do not have eclipse glasses yet should get a pair as soon as they can to make sure that they have them in time for the big event on Aug. 21.

There are many places online to order eclipse glasses to get them sent to your house, but the American Astronomical Society recommends purchasing them from manufacturers and certified vendors.

It may be wise to order them sooner rather than later as some websites are expected to sell out due to the high demand for glasses.

Some stores across the country are also beginning to sell eclipse glasses, especially those located in the path of totality. Some public libraries will also have a small supply of glasses available.

4. How to view the eclipse without eclipse glasses

People that can't get a hold of eclipse glasses by Aug. 21 can still view the celestial event indirectly in many different ways.

One of the most common ways is to make a simple device called a pinhole viewer, which can be made with a piece of paper and an empty cereal box.

"Another way to do this is to punch a small hole in a card, and with the sun at your back, project the sun through that hole onto a second card, a wall or the ground," Fienberg said.

These projections will not be round dots, but little crescents that look the same as the current phase of the partial solar eclipse.

The same crescent shadows can be seen by using any object with little holes in them, such as a spaghetti colander or slotted spoon.

There are also ways to view the eclipse indirectly without any equipment.

"The easiest way which needs no equipment at all is to find a nice leafy tree and look under it during the partial phases of the eclipse," Fienberg said.

This will reveal plenty of crescent suns on the ground in the shadow of the tree where light peers through.

Stretching out your arms and crossing your fingers over each other like a web can also reveal crescent-shaped shadows.

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