A photo posted onto a mother’s Facebook page could have saved her baby’s life after a friend spotted a cancer in the infant’s eye.

Kelly Glazbrook, from Minlaton on South Australia’s Yorke Peninsula, posted the photo of her son Finn onto Facebook, and friend Annalisa Wood spotted something suspicious.

“I was kind of nervous because I didn’t want to worry her in case it was just a camera issue,” Annalisa said.

Annalisa, a medical scientist, suspected a tiny white reflection in Finn’s eye could be a sign of retinoblastoma – an aggressive children’s eye cancer.

Finn’s mother booked him in to see the optometrist, who confirmed the suspicion, and Finn was soon rushed to the Women’s and Children’s Hospital in Adelaide, two-and-a-half hours away.

“We went from having a perfectly normal six-month-old to, 24 hours later, we had pretty much a cancer diagnosis,” said Kelly Glazbrook.

“He seemed perfectly normal, there was absolutely no signs or symptoms.”

Doctors had planned to remove the eye, but instead opted for chemotherapy.

Finn has already undergone three doses of chemotherapy, and is to undergo another three next year.

While he has lost central vision in his eye, he still has peripheral vision.

Annalisa has become a hero to the Glazbrook household.