And no, sunglasses are not the right protection.
This August 21st, the moon will slip between the earth and the sun and the entire world will go black. Well, not the entire world—just a 70 mile-wide path starting in Oregon and ending in South Carolina. The Great American Eclipse is the first total solar eclipse in history that will only be seen from the US. And if what you read is true, it's going to have some bizarre health consequences.
For instance: Black energy could possess you if you don't fast on eclipse day—or take a bath before you eat the next day. That's the advice Spiritual Science Research Foundation (SSRF) gives on its website. Then again, SSRF also teaches that solar eclipses are caused by ghosts eating the sun and that these ghosts will gobble up your sattva, rajas, and tamas, the three fundamental forces of nature according to Ayurveda yoga. The SYDA Foundation, meanwhile, claims a solar eclipse reduces digestive powers and recommends eating lightly. Expect your energy to be eclipsed two or three days before and after its passing, SYDA advises.
Of course, it's highly unlikely that an eclipse ghost will eat your soul. Also, if your stomach rumbles when the sky gets dark, it's probably because this eclipse starts at 1:16 pm Eastern—right around lunch time. But can a total solar eclipse actually affect your health? Yes; in less unusual ways:
First and foremost, if you look straight at one without proper eye protection, you can go blind. No hyperbole. "Protect the eyes," Thomas Zurbuchen, Associate Administrator for NASA Science Mission Directorate, said during a press conference about the upcoming event. Looking directly at the sun is never a smart idea, eclipse or not. The human eye is made of many parts. Think of the front part, the cornea, as a window. It's clear and separates the rest of your eye from the outside. Just like your windows at home, if something gets on the cornea, you can't see out. Looking at the sun can burn the cornea. Over a lifetime of looking, these burns form cataracts.
During an eclipse, though, there's added danger, since people are more likely to gawk, and because they might think they're safe since the sun is partially covered. According to Albert Pang, a board-certified optometrist at Trinity Eye Care in Plano, Texas, "Looking at a solar eclipse without protection can cause permanent damage to the retina, that is, the inside layer of the eyes. We call it solar retinopathy. The radiation of the sun can burn your retina within a minute." Per NASA: "Exposure of the retina to intense visible light causes damage to its light-sensitive rod and cone cells. The light triggers a series of complex chemical reactions within the cells which damages their ability to respond to a visual stimulus, and in extreme cases, can destroy them."
Pang says this damage is permanent and "has no cure. It is similar to using a hot iron to burn your eyes." Or as NASA puts it, "the high level of visible and near-infrared radiation causes heating that literally cooks the exposed tissue." Since there are no pain receptors in the retina, you won't even know the burning happened "for at least several hours after the damage is done."
This doesn't mean you should be afraid to watch the eclipse, though; just wear the right eye protection. And no, sunglasses are not the right protection. You need special eclipse glasses. The lightweight specs are made from cardboard and solar filters that Pang says "block out all the UV and infrared light as well as 99 percent of the visible light to ensure none of the sun's radiation will cause any damage to your eye." The filters are "100,000 times darker than your regular sunglasses," so they're worth the $1 they sell for online. You can also get eclipse glasses for free at more than 1,500 libraries nationwide. Wherever you get yours, make sure they're made by an ISO 12312-2 certified manufacturer so you know they're made correctly. (The International Organization for Standardization certifies everything from large assembly-line manufacturing machines to foreign language translation. ISO certification means something is built to standard.) NASA recommends Rainbow Symphony, American Paper Optics, Thousand Oaks Optical, and TSE 17.
Once you have yours, Zurbuchen says, "Make sure [they're] truly on top of the eyes," and not askew. If you have children, he also recommends they practice wearing the glasses before the eclipse "so they really get used to it and understand that's how it feels." This lowers the risk of little ones pulling the glasses off.
Zurbuchen's next piece of health advice: Sunblock. Unlike with the eyes, there's no special "eclipse sunburn." Just regular sunburn that could come from spending all day outside. And, since you will be in the heat all day, he also says, "Be sure to bring enough water." You may also want painkillers on hand. During a total solar eclipse, temperatures can drop up to 20 degrees. If stepping into air conditioning after being in the heat gives you a headache, as it does for some people, expect a similar effect here.
That's it for how the eclipse can affect your health from the skies; now let's talk about health considerations created on the ground.
NASA currently predicts that more people will see the Great American Eclipse than any other total solar eclipse in history. 200 million Americans live within a day's drive of its path. The roads will be packed.
"Drive safe" advice is standard for heavy traffic, but eclipse tourism brings concerns of its own: The vast majority of towns in totality are Andy Griffith-level small. Take Hopkinsville, Kentucky, for example, the point of greatest eclipse. Only 31,577 people live there. The town expects more than 100,000 guests. City leaders have spent two years making sure Hopkinsville's ready, but not every eclipse town will have gone to as much effort.
That's why Central Oregon Emergency Information Network recommends anyone living in the eclipse path fill prescriptions before August 21. Traffic could keep you from getting to the pharmacy, and you don't want to miss that day's dose.
As for your sattva, rajas, and tamas—those three balancing agents from Ayurveda—whether you believe in that sort of stuff is up to you. These are the known, scientific ways the event can affect your health, but psychologically, total solar eclipses often prompt a deep, emotional reaction to the unknown. Per NASA, even, such events "have stimulated responses that run the gamut from human sacrifices to feelings of awe and bewilderment." So if you want to fast and bathe per the sun-eating-ghost believers, we won't get in your way. Just do it with those special glasses on.
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