How To Safely View An Eclipse & Protect Your Eyes From The Sun
On Monday, August 21st, the U.S. will experience its first solar eclipse since 1979. Whether you're planning a road trip to the "path of totality," or just hoping to take a quick peek over your lunch break, it's important to take proper precautions, because staring directly at the sun, even when it's partially covered, is generally a bad idea that can result in permanent eye damage. Fortunately, there are a few ways you can safely view an eclipse.
Contrary to what you may have learned in grade school, the sun is not in fact brighter during an eclipse. People are only more susceptible to injury during an eclipse because it's easier to stare at the sun for an extended amount of time when it's partially covered, and because our retinas don't have pain receptors, the UV rays can burn light-sensitive cells in our eyes before think to look away.
And it just takes a few seconds of exposure to do a lifetime of damage. Lou Tomososki, for example, a 70-year-old Oregon man, has experienced vision problems ever since he looked directly at a partial eclipse back in 1962.
"“It doesn’t get any worse and it doesn’t get any better,” he told his local television station, KGW. “You know how the news people blur a license plate out? That’s what I have on the right eye, about the size of a pea, I can’t see around that.”
As long as you are careful though, you can safely enjoy what promises to be a spectacular celestial event. Here are some tips for how to view the eclipse safely.
Only look at the sun during the totality
This only applies to people who will be viewing the eclipse from within the "path of totality" -- the 70-mile-wide strip where people will be able to see the moon block the sun completely. Depending on where you're located, this total eclipse might last up to two minutes and 40 seconds. According to NASA:
"If you are within the path of totality, remove your solar filter only when the moon completely covers the sun’s bright face and it suddenly gets quite dark. Experience totality, then, as soon as the bright sun begins to reappear, replace your solar viewer to look at the remaining partial phases."
Everyone outside the path of totality should use some sort of solar filter or protection throughout the event.
The safest and easiest way to view the eclipse is with a pair of special eclipse glasses with solar filters, which filter out 99.9 percent of light. This means the sun should be the only thing visible through the lenses. And no, your regular Ray Bans aren't going to cut it, according to NASA, because they allow "thousands of times too much sunlight" through, which can permanently damage your eyes.
“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,” said Rick Fienberg, press officer of the American Astronomical Society. “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."
For those of you who weren't able to get any eclipse glasses in time, you can still view the eclipse indirectly with some sort of pinhole viewer, which you can make with an empty cereal box, or, as Rick Fienberg suggests: “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."
Pinhole viewers are safe because you're not looking directly at the sun, just a reflection of the sun which will appear as a crescent that "looks the same as the current phase of the partial solar eclipse."
Solar filters for telescopes
For those of you hardcore astronomers who want to bring some heavy-duty viewing equipment to the eclipse, make sure you have a fitted solar filter for any magnification devices you want to use, like telescopes or binoculars, because even eclipse glasses won't protect you from magnified rays of sunlight.
"Solar-viewing glasses are not powerful enough to protect your eyes from magnified sunlight," says Space.com. "Even if you are wearing solar-viewing glasses, viewing the disk of the sun through a magnification device will result in serious eye damage if the device is not equipped with a proper solar filter."
"Seek expert advice from an astronomer before using a solar filter with a camera, a telescope, binoculars, or any other optical device."
If you completely forgot about the eclipse and didn't have time to buy glasses or make your own pinhole viewer, Fienberg suggests the easiest way to view the event "is to find a nice leafy tree and look under it during the partial phases of the eclipse."
Like looking through a pinhole viewer, the light beneath a tree will reflect the different phases of the eclipse.