Why You Need Eclipse Glass, to Stare at it?

With the Aug. 21 solar eclipse just days away, you’ve likely heard the warnings to never look directly at the sun without proper eye protection. And for good reason: A recent case illustrates the real danger of doing so — A 12-year-old girl in Florida damaged her eyes by looking at the sun for 1 minute, according to a new report of the girl’s case.

One day after staring at the sun, the girl went to an ophthalmology emergency room because her vision had become blurry, according to the report, published today (Aug. 18) in the journal JAMA Ophthalmology.

The girl had a condition called “solar retinopathy,” which means her eyes were damaged from looking at the intense light of the sun, said Dr. Kara Cavuoto, an ophthalmologist at the Bascom Palmer Eye Institute at the University of Miami Health System. Cavuoto and co-author Dr. Ta Chen Chang, also an ophthalmologist at the same institute, treated the patient. [2017 Total Solar Eclipse: Everything You Need to Know]

Solar retinopathy is thought to occur when extremely bright light creates molecules known as free radicals in a person’s eyes. These highly reactive molecules can kill cells in the retina, leading to blurry vision, according to the American Academy of Ophthalmology (AAO).

The girl’s case didn’t take place during a solar eclipse, but “there’s no difference in risk between looking at the sun during a [solar] eclipse versus any other time,” Cavuoto told Live Science. “People often stare at the sun for prolonged periods of time during an eclipse and may underestimate the harm the sun is causing to their eyes.”

In solar retinopathy, the central part of the retina, called the macula, is damaged, Cavuoto said. In particular, the damage occurs in a central pit in the macula called the fovea, which is responsible for sharp vision. “This results in blurred vision or a blind spot in one or both eyes,” she said.

The condition isn’t painful, and the symptoms don’t start immediately after a person looks at the sun. Generally, a person starts to notice the effects a few hours after looking at the sun, Cavuoto said. In the girl’s case, she noticed that her vision was blurry several hours later, and by the following day, her vision had gotten worse.

The doctors noted in the report that the girl had glaucoma, a condition that causes increased pressure in the eye and can also damage vision. (The girl already had glaucoma before staring at the sun; the condition did not result from that incident.) It’s possible that because the girl’s vision was already decreased, she might have stared at the sun longer to see all of the details, Cavuoto said.

In some cases of solar retinopathy, people’s vision may improve within six months, but they rarely return to “normal” vision, Cavuoto said. The girl’s vision, however, did not improve, according to the report.

Despite the name solar retinopathy, staring at the sun isn’t the only cause of the condition. Activities such as welding, which emits a very bright light, and misusing a laser pointer can also cause solar retinopathy, Cavuoto said.