A total solar eclipse will be visible across North America Monday, and Callaway County is one of several cities on the direct viewing path.
The event will be the first total solar eclipse visible from the continental United States since 1979, and thousands of people are expected to turn their gazes skyward. A University of Missouri Health Care ophthalmologist has viewing tips to safely enjoy the rare event.
"A total solar eclipse is an awe-inspiring event, but it's still important to remember to protect your eyesight," said Frederick Fraunfelder, M.D., director of ophthalmology at MU Health Care and chair of the Department of Ophthalmology at the MU School of Medicine. "We're all taught never to look directly into the sun, and for the majority of this eclipse, that rule still applies. Looking at a partial solar eclipse is as dangerous as looking at the unblocked sun and can cause damage to your retina, the light-sensitive nerve layer in your eye."
The 2017 eclipse is expected to last up to three hours as the moon begins to block out the face of the sun, starting about 11:45 a.m. For the majority of this time, it's unsafe to look directly at the sun without special solar filters, such as eclipse glasses or through a pinhole camera. During the partial eclipse phase, Fraunfelder recommends viewers wear eclipse glasses specially designed to filter harmful ultraviolet rays. Exposing the retina of the eye to intense light can cause damage to its light-sensitive rod and cone cells, which can lead to a temporary or permanent vision loss. Eclipse glasses filter UV, infrared and intense visible light rays and protect the eyes from damage.
However, for approximately two minutes and 40 seconds, the moon will completely block out the face of the sun, leaving only the sun's outer atmosphere, or solar corona, visible. During this brief period — 1:13-1:15 p.m. — it will be safe to look at the eclipse with the naked eye, as the eclipse will be about as bright as a full moon.
"The sun's UV rays can cause eye damage and have been linked to the development of cataracts, macular degeneration, eye cancers and other conditions that can cause vision loss," Fraunfelder said. "Looking directly at the sun during an eclipse can cause solar retinopathy, which can lead to a temporary or even permanent decrease in vision acuity. It's important to wear UV-blocking sunglasses when outdoors in everyday life, but remember that standard sunglasses don't offer adequate protection for viewing an eclipse."
"We all want to experience the splendor of a total solar eclipse, but we want to walk away with lasting memories, not lasting eye damage," said Angela Speck, professor of astrophysics and director of astronomy in the College of Arts and Sciences at MU. "By taking a few simple precautions, we can all experience a safe, once-in-a-lifetime eclipse."