The Chicago area will soon witness a rare solar eclipse, and while the region won't be in the so-called "path of totality," experts say there are some things you should know before heading out to watch the event.
After years of anticipation, a total solar eclipse that will be visible across much of the United States is less than two months away -- and Illinois will play a major role in it.
While some parts of the state are in the coveted path of totality on April 8, meaning they will see the sun completely covered by the moon for several minutes, Chicago and its surrounding suburbs will still experience an estimated 94% totality. That number is higher than the eclipse in 2017 and even higher than any partial eclipses expected in the near future.
But while the area isn't among those that will see 100% totality, that doesn't mean you won't need glasses to view it. In fact, it means viewers will need them even more.
"So a solar eclipse is no more dangerous to look at than just the regular sun," Michelle Nichols, director of public observing at the Adler Planetarium, told NBC Chicago. "You don't go out staring at the sun on any given day. You don't go out staring at a solar eclipse on any given day. The only people who can see the sun safely with just their eyes are the people who see totality - that is safe to look at. Any other view of the sun, you must have legit, noncounterfeit solar viewing glasses to be able to do it. This does not work with sunglasses or things like that. So we tell people just don't stare at the sun period. And that will cover you for non eclipses and for eclipses."
An article from Travel + Leisure magazine agrees, citing the American Astronomical Society.
"The American Astronomical Society recommends you wear solar eclipse glasses at all times while viewing a solar eclipse," the article said. "If you are not in the path of totality, you will only ever see the partial eclipse, so it's crucial you keep your eclipse sunglasses on at all times to avoid eye damage."
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Those who are in the path of totality will be able to safely look at the eclipse only during the brief window where the sun is entirely covered.
Here's what to know:
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What can happen if you don't have glasses while viewing a solar eclipse?
According to the Adler Planetarium, viewing the solar eclipse without glasses can result in irreversible eye damage within seconds, and as your eyes lack the nerve endings to register pain as it's occurring, it'll be too late by the time you know.
"The amount of light coming from the sun is intense," Nichols said. "And so you have a lot of visible light, you also have infrared light and ultraviolet light. It's the infrared and ultraviolet that you especially don't realize that your eyes are being subjected to. You don't have nerve endings on the back of your eyeball, so you could be experiencing a burn and not know it. And that burn might turn out to be permanent."
How can you tell if your glasses are safe to use?
Nichols stressed the importance of ensuring that viewing glasses are not counterfeit, however, noting that there's no real way to detect real glasses versus counterfeit ones just by looking at them.
"The glasses if they're counterfeit, they may appear fine, because maybe they're dark enough that you can that it appears like you can safely look at the sun. But what you don't know is are they letting through ultraviolet and infrared light. That's the thing that I would worry about the most," she said.
She suggests purchasing through suppliers deemed "safe" by the American Astronomical Society.
"Just be careful and don't just assume just because it says safe glasses that that they actually are because anyone can write that," she said.
According to Space.com, ISO-approved solar eclipse glasses must meet the following safety requirements:
- No more than 0.00032 percent of the sun's light may be transmitted through the filters.
- The filters must be free of any defects, such as scratches, bubbles and dents.
- Handheld viewers must be large enough to cover both eyes.
- Labels on the viewers (or packaging) must include the name of the manufacturer, instructions for safe use and warnings of the dangers of improper use.
What if you still have glasses from previous solar eclipses?
For those who still have glasses from the last solar eclipse, those could still be good. Nichols said they could still be usable.
"If folks have materials leftover from 2017, as long as those were legit and purchased from a legit vendor in 2017, you can just check it by shining a bright flashlight through it," she said. "Just make sure there's no pinholes or punctures or tears or rips or anything."
If you're not sure, Nichols said it's best to not risk it.
"When in doubt, throw it out. You don't want to take any chances with with your eyesight," she said.
What can you do if you don't have glasses?
Another option for people who don't have glasses is to create a pinhole image, Nichols said.
"There are indirect ways of seeing the eclipse," she said. "You can make a pinhole projector and what that means is take an index card, a piece of aluminum foil, something that you can stick a little hole into, line up that hole with the sun and project an image of this on down onto the ground. And that's a way to indirectly view an image of the eclipse."
Just don't look directly through the hole, she said, adding that "that would be putting a focused image of the sun on your eyeball and you don't want to do that."
What about viewing through your phone?
According to Nichols, using your phone to capture the solar eclipse could also be damaging.
"Don't just point your phone at the sun either because you'll fry your phone camera, so just don't do that either," she said.
She noted, however, that some companies make filters or covers for phone camera lenses to safely capture a solar eclipse.
NASA said viewers should not use solar glasses while trying to view the eclipse through a phone or camera lense.
"Do NOT look at the Sun through a camera lens, telescope, binoculars, or any other optical device while wearing eclipse glasses or using a handheld solar viewer — the concentrated solar rays will burn through the filter and cause serious eye injury," the agency said.
However, those who use a proper filter on their phone or camera lense should be able to safely view the eclipse through those devices.
"When viewing a partial or annular eclipse through cameras, binoculars, or telescopes equipped with proper solar filters, you do not need to wear eclipse glasses. (The solar filters do the same job as the eclipse glasses to protect your eyes)" NASA reported.
