—made Spencer believe it unlikely he’d pass along the disease.

But having defied the odds, the 41-year-old Spencer has made it his life’s goal to improve Andrew’s chances of fulfilling his dream of becoming an Olympic swimmer.

“He’s going to be the one to change the face of cancer,” Spencer said of his son.

Major strides have been made in the treatment of retinoblastoma in the time since patients like Spencer were flooded with radiation — usually causing secondary cancers, even if effective against its target.

Instead, Andrew’s tumors have been removed with the precision of specialized lasers.

“I had three of the best doctors in the world working with me,” Spencer said of his son’s terrifying first days. “I was going to fight for his life, and then I was going to fight for his eyes.”

Early detection remains key for today’s more sophisticated treatments to work.

In Spencer’s case, he was already 2 years old when he was diagnosed, after the light from a window caught one of his eyes and his mother could see it had turned brown.

That was when Spencer first met ophthalmologist Dr. Norman Byers, who removed his cancer-ridden eye.

Spencer was able to keep the other eye until March 2012, though he’d lost vision in it a few years before.

He considers it a great gift he was able to see his son Andrew during the first two years of his life.

He can account for all the reasons Andrew is doing as well as he is, including retaining 20/20 vision. But the factors that have made Spencer one of the longest-living people with bilateral retinoblastoma are a bit harder to explain.

“I say it’s family, it’s faith, it’s doctors and it’s luck,” Spencer said.

With his tall, muscular build, a ponytail that reaches the middle of his back and sunglasses that usually cover his empty eye sockets, Spencer can look like an NFL player on a day off. His body language and ability to follow voices and other sounds make his blindness something others frequently don’t pick up on right away.

But with a noncancerous brain tumor and other health problems caused by many years of radiation therapy, Spencer describes his current condition as cancer-free but not well.

The retired Dr. Byers, even with all the medical terminology at his disposal, said he couldn’t put it any better.

He knew Spencer from the time of his first surgery in the late ’70s until 1988. After a 22-year gap, he was stunned to learn in 2010 that Spencer was not only still alive but helping a son survive and thrive with retinoblastoma. Spencer and Andrew are only the second parent-and-child retinoblastoma patients he’s ever encountered.

Byers said a child diagnosed as early as Andrew has a fighting chance today for a normal life — including Olympic aspirations.

“There’s no reason why that couldn’t be a realistic goal,” Byers said.

However, Andrew’s fight with cancer, even with its early detection, has been far from easy. He’s had numerous surgeries throughout his young life and undergoes a search for new tumors every three months.

Andrew said he’s been inspired by his father’s fight.

“What happened to him as a kid made him fight for me. And that meant everything to me,” Andrew said. “It hurts me when kids get affected by retinoblastoma and don’t get as healthy as me.”

Even after he lost the vision in his remaining eye, Spencer fought for a few years to keep it in the hope a way might be found for him to see his family again one day. When it became clear that keeping the eye was threatening his life, Andrew’s was among the voices that persuaded him to give it up, Spencer recalled emotionally.

“My son said, ‘You’re Superdad without eyes.’”