Next month, the heavens will serve up a total solar eclipse viewable across the United States. As excitement builds over the rare spectacle, associations are warning about the risks of viewing the eclipse without the right protective gear.
Less than a month from now, a solar eclipse will be viewable across the mainland U.S. for the first time in nearly 40 years, and with the path spanning the Lower 48 from coast to coast, millions of people are going to get a look at a rare sight.
But before the big event on August 21, several associations are warning eclipse watchers of the risks.
The American Astronomical Society (AAS), the American Academy of Ophthalmology (AAO), and the American Optometric Association (AOA) are advising people who plan to view the eclipse to get their hands on proper eye protection.
“The eclipse is a truly rare moment that the whole country is able to experience together,” AOA President Christopher Quinn said in a news release. “As America’s primary eye health and vision care doctors, the AOA and our member doctors of optometry are excited to help educate everyone about how they can enjoy this once-in-a-lifetime experience while safely protecting their eyes.”
The group, which offers a resource page on its website, says that within the path of totality—a 70-mile-wide swath extending from Oregon to South Carolina—the eclipse can be viewed safely with the naked eye during the time that the moon completely covers the sun (about two minutes and 40 seconds, or less). But looking directly at a partial eclipse without proper equipment puts observers at risk of solar retinopathy, a form of retina damage that can be severe.
“Viewing the sun directly, even for brief periods, can cause permanent damage to the retina and result in blindness,” AAO spokesman Dr. Russell N. Van Gelder said in a news release. “I have patients who viewed the sun [during an eclipse] 40 years ago who remain without central vision in their affected eyes.”
All three associations recommend purchasing specialized solar glasses designed to block out dangerous ultraviolet and infrared rays. Homemade glasses or sunglasses are not enough.
“The only safe way to look directly at the uneclipsed or partially eclipsed sun is through special-purpose solar filters, such as ‘eclipse glasses’ or handheld solar viewers,” AAS states on an informational page. “Homemade filters or ordinary sunglasses, even very dark ones, are not safe for looking at the sun (fact: special-purpose solar filters are about 100,000 times darker than ordinary sunglasses).”
The AAS resource page includes information about suppliers of protective eyewear that meets current international standards.
“Looking directly at the sun through anything that isn’t specially made to deal with all that visible light and invisible radiation is a recipe for serious eye injury, perhaps even blindness,” AAS warns.
The associations aren’t alone in spreading the word about safety. NASA’s guidelines offer similar recommendations on how to experience the eclipse with eyesight intact.