A two-year-old British girl was set to have her eye removed Monday after being diagnosed with a deadly, fast-spreading eye cancer discovered thanks to a flashing light on her toothbrush.

Katie Lolley was using the $4.80 brush, whose light flashes to show how long children should use it, when her mother, Rebecca, noticed a strange white reflection in her retina. She alerted doctors, who discovered a rare retinoblastoma—an often-fatal tumor that can triple in size in just 10 days.

"If it wasn't for that flashing toothbrush, we may never have seen the tumor—at least, not till it was too late," the 29-year-old mother said.

She added, "We bought the brush because Katie liked the look of it. When we got it home, we turned the bathroom lights out so Katie could try it. She loved it but, when I looked at her face in the dark, I could see the lights creating a strange white reflection in one eye. At that point, we decided to take her straight to the hospital."

Rebecca and Katie's dad, Karl, 31, were devastated by the diagnosis but said that "even though it's awful that Katie has to lose an eye, we're so relieved we caught the tumor in time."

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