ABC News featured an interview with Julie Fitzgerald, a mom who noticed a white glow in her son Avery’s eye after taking a picture of him with her smartphone.

Julie took her son to the eye doctor where the physician diagnosed him with retinoblastoma, a rare form of eye cancer.

The key for treating retinoblastoma is to catch it early. Unfortunately, surgeons had to remove Avery’s eye because 75 percent of it was covered in tumors. But due to the camera flash, doctors were able to prevent the cancer from spreading to the rest of Avery’s body.

Although Mayo Clinic Ophthalmologist Michael Stewart told USA Today this isn’t a definitive way of detecting this cancer, so a follow-up appointment with an eye doctor is encouraged.

Watch the video below from the Childhood Eye Cancer Trust to learn more about how retinoblastoma can be discovered.