It’s not unusual for parents to find a special sparkle in their children’s eyes, but there was something else going on with Grace Fetterman, the 8-year-old daughter of Pennsylvania Lt. Gov. John Fetterman.

In photographs, when Grace’s siblings had the telltale red eye of a camera’s flash, Grace had a yellow glow in one pupil. Her mother noticed the oddity and called the family doctor. With that, she saved Grace from a serious and rare eye disorder that can lead to blindness, Gisele Barreto Fetterman told ABC27 in Harrisburg in an interview posted Tuesday.

“I don’t want to be an alarmist,” Gisele Fetterman recalled telling the doctor, “but I’m looking through my daughter’s photos and every photo has a yellow glow in one eye.”

“He said, ‘Pull her out of school and bring her in immediately,’” Fetterman told ABC27.

Grace was diagnosed with Coats’ disease, which occurs when blood vessels in the retina develop abnormally, according to the National Institutes of Health. Symptoms, usually in just one eye, typically begin in childhood, and include a consistent white or opaque spot in the pupil.

Left untreated, Coats’ disease can lead to detached retina, glaucoma, and blindness.

Treatment varies, depending on how the condition has progressed.

Grace’s condition was caught early enough that she was able to save her eyesight by wearing glasses, her family told ABC27.

A white, yellow or opaque eye glow could be a sign of many eye conditions, including a deadly retina cancer that affects about 300 children a year, said Carol Shields, chief of ocular oncology at Wills Eye Hospital.

An eye glow can also be an early sign of a cataract or infection, she said.

“The most important thing a parent can do, when it comes to the eyes, is look at their child and make sure their child doesn’t have glow in their eyes, and that the eyes are both looking straight,” Shields said. “Those two features can tell us a lot about what’s going on with the eyes and how well the child sees.”

The glow is most often detected in photographs, but may also be visible if looking at the child’s eyes in a well-lit room. Depending on how advanced the condition is, the glow may only appear when the child is looking in a specific direction, she said.

Parents should consult a doctor as soon as they see a glow in their child’s pupil — even if it does not show up consistently in every photograph, Shields said. Parents are much more likely than a pediatrician to notice a glow, she said.

Last month, the lieutenant governor urged parents to learn more about the issue and take a closer look at their children’s pictures. He included a link to the organization Know the Glow, which educates families about glow-related eye disorders.

“So thankful Gisele noticed and for the resources online,” he wrote on Twitter. “Parents: Know the Glow.”