When the ophthalmologist looked into a 26-year-old's eye in 2017, it was a worst-case scenario. The distinctive contours of the solar eclipse the woman stared at days prior were etched onto her retina.
The case of the Staten Island woman who watched the eclipse through faulty glasses was notable enough to be chronicled by doctors from Mount Sinai's New York Eye and Ear Infirmary in JAMA Ophthalmology, a medical journal, because these cases are, luckily, rare.
“It's a very focused beam of high-energy light from the sun itself,” said Dr. Avnish Deobhakta, an ophthalmologist at the Mount Sinai infirmary who treated the woman. “It can actually destroy parts of the retina, and certainly destroy it in the shape of an eclipse.”
The woman told Mount Sinai doctors she had gazed at the moon passing in front of the sun through what she believed were protective glasses. In scans, the damage on her left retina, the area at the back of the eye where the brain receives images, resembled the shape of a partial eclipse. She told a local TV station that year when she closed her eyes, she saw a sun-eating-moon image that "looked like Pac-Man" or "a crescent moon."
Looking up when you're within the 115-mile-wide path when the moon completely covers the sun for a few minutes is safe, experts say. But directly staring at the sun before and after the total eclipse, or watching a partial eclipse outside the path of totality without proper eye protection can result in permanent damage including blurred and altered vision.
While rare, eye damage from watching a partial eclipse happens because a person's natural response to squint when looking at sunlight does not get triggered. In the leadup to the April 8 solar eclipse, doctors and a rare set of eclipse watchers are warning about watching this planetary event without adequate eclipse glasses or with the naked eye.
It’s hard for experts to know or even estimate how many people experience eye damage from solar eclipses. Since looking at an eclipse does not cause complete blindness, people with permanent damage may not know they have it or report it to a doctor. The 2017 eclipse, which passed from Oregon to South Carolina, is thought to have caused about 100 cases, according to the American Astronomical Society. A national survey by NASA and the University of Michigan estimated over 150 million people witnessed that eclipse.
The 2024 eclipse is expected to have more people watching because it is passing over several large cities in the U.S. and Mexico.
Experts urge people to plan before they head outside to stare at the sun.
“Human nature is to take a shortcut anywhere we can,” Dr. Ron Benner, an optometrist in Montana and the president of the American Optometric Association, a professional group, told USA TODAY. “But in this case, shortcuts can cause permanent damage.”
When there isn’t an eclipse, humans naturally squint or are forced to look away from the sun’s brightness. People often also wear sunglasses to protect against harmful UV rays.
But during a partial eclipse, the moon’s shadow allows people to stare at the sun longer without experiencing that intense glare. The high-energy rays cast down during that time are akin to a laser pinpointing at the eye. Without feeling the usual sting in their eyes, people are exposed to harmful rays for a longer period, Deobhakta said.
There's a misconception that eye damage of this nature is a sunburn, said Benner, from the optometric association. Dangerous light and radiation exposure, when you turn your eyes directly to the sun, can permanently damage retinal cells at the back of the eye. The retina plays an essential role in helping the brain process images.
About four hours after the Staten Island woman watched the eclipse – with glasses she thought were protective – her vision became blurry and color distorted, according to the JAMA study from Mount Sinai.
