Diagnosed with eye cancer at just 16-weeks-old, a six-month course of chemotherapy combined with laser treatment and surgery reduced the tumours but his left eye could not be saved.
By seven months he was blind in one eye and had limited sight in the other.
Then, during a routine hospital check-up when he was five, his parents were told the tumours had returned.
This time, Kelsey had chemo injections directly into his eye but the extreme treatment was unsuccessful leaving him totally blind.
Yet, despite the devastating news, his spirit remained unbroken. As they traveled home from the hospital he told his devastated mum Jo, "You can't always have what you want Mum, can you?"
Today, Kelsey has artificial eyes but his determination to live a normal life sees him attend mainstream school where he is a Grade 2 reader and writer of Braille and a touch-typist.
He's also a keen dancer, plays football and dodgeball and incredibly has even learned to ski and abseil.
"I don't think anything is off-limits," insists Kelsey. "I find someway to do it. It's as if there's a brick wall in front of me and I just have to make a hole in it."
What would he say to others in his situation?
"Don't be angry. Don't be sad. Just get on with it. There's nothing you can't do."
Kelsey, from Watford, has also has even become a member of the local Hertfordshire Council's Children's Commissioning Forum, helping to ensure that disabilities are taken into account when new children's activities are being planned.
"It's important that kids with disabilities don't feel left out," he says. "You want to be able to do the things that your friends are doing."
To help determine how mainstream children's activities could be more inclusive of disabled youngsters, he has spoken to 40 delegates, including representatives from the police and local council, about how his blindness affects his life.
Proud Jo said: "He told them what it was like to be blind and explained that simple changes could make a massive difference.
"We're extremely proud. He's actually made it so easy for us because of his own attitude.
"He's always led the way and he thinks everything is for the taking.
"When we were told he would lose his sight we could have crumbled, but because of Kelsey's approach we've been forced to carry on. When he's coping so well how can we not?"