Make the eclipse easy on your eyes
Staring at the sun is never a good idea. Its retina-burning radiation can leave a permanent dark spot in vision. Basic instinct usually keeps people from doing it. The exception:
An eclipse!
The extraordinary marvel of seeing the moon approach and cover the sun, as will happen in the Buffalo sky on the afternoon of April 8, entices people to look up without protection, said Andrew Reynolds, a University at Buffalo clinical associate ophthalmology professor.
“Eclipses are this very rare thing, where for three minutes we’re tempted to look at the sun,” said Reynolds, who is also a pediatric ophthalmologist. “Anytime you look at the sun, there is a chance of retinal damage.”
The sun’s energy, strong enough to grow all the plants on earth, can also burn the light sensitive part of the eye, causing solar retinopathy.
“Tons and tons of radiation comes from the sun and that is damaging to our very sensitive retinas,” said Reynolds.
During the eclipse there will be a safe viewing time, of almost four minutes, when the moon covers the sun completely for “totality.”
In Buffalo the sun will be fully obscured and safe to look at from 3:18:20 p.m. to 3:22:06 p.m. Monday, April 8. If clouds don’t get in the way, views of the feathery corona of the sun’s outer atmosphere may be clear.
“That amount of light is about equivalent to a full moon,” said Reynolds.
The problem, he said, is that the time span of totality is so short that people may mistakenly think it’s safe without glasses when it’s not.
“The sun doesn’t tell you when it’s in totality, right?” Reynolds said. “If you’re looking and you think it’s totality and 10 percent of the sun is actually showing that’s going to be too much sun for your eyes.”
To protect eyes and watch the eclipse from its beginnings as the moon moves and covers the sun – starting at 2:04:56 p.m. — people must wear special viewing glasses. Look for ones made to an international standard certified and marked “ISO123 122.”
“I would strongly, strongly, strongly encourage people to get these ahead of time,” Reynolds said. “Regular sunglasses don’t count. Those aren’t nearly dark enough to protect your eyes.”
Retired NASA astrophysicist Fred Espenak describes sun viewing hazards this way on his mreclipse.com site: Permanent damage can come from looking at the sun directly, through a camera viewfinder, binoculars or a telescope — even when only a thin crescent of the sun or its beaded edge remains.
“The 1 percent of the sun’s surface still visible is about 10,000 times brighter than the full moon. Staring at the sun under such circumstances is like using a magnifying glass to focus sunlight onto tinder. The retina is delicate and irreplaceable. There is little or nothing a retinal surgeon will be able to do to help you,” wrote Espenak.
Risk of harm varies with the individual, said Reynolds. Older people may have cataracts that would make the impact of sun gazing less severe. Younger people or those with retina-related diseases are more at risk for sun damage because their eyes let in more light.
“Because of all these factors that are essentially unknowable for every individual person … the answer is, ‘There’s no safe dose,’” he said. “There is no, ‘Oh yeah sure, you’ll be fine at 10 seconds. You’ll be fine at 20 seconds …’”
One way to be sure about when it is OK to look without glasses is to view along with an expert guide. Some public events, like the Eclipse Fest at Buffalo State University and Sahlen Field gathering, will include NASA scientists and other experts who will talk people through what is happening in the sky. Eclipse expert Fred Espenak also suggests using the Solar Eclipse Timer phone app, solareclipsetimer.com.
“The most stunning part is the totality and you get the solar flares and the corona,” Reynolds said. “But one minute on either side of that three minutes is enough to cause permanent, long term vision trouble … So, it’s a razor’s edge of safety.”
Resource links
Visit Buffalo Niagara Buffalo Eclipse information: visitbuffaloniagara.com/buffalo-eclipse-2024
Advice from NASA: science.nasa.gov/eclipses/safety
Details about the eclipse timing in Buffalo: buffalony.gov
The Solar Eclipse Timer phone app, $1.99, with geolocation and in-the-moment guidance, as recommended by Fred Espenak, retired NASA astrophysicist: solareclipsetimer.com.
