Nearly 30,000 people will participate in the 41st Marine Corps Marathon on Sunday. But it is the youngest runner that may have the biggest goal.

The 13-year-old Pennsylvania native, Nikolas Toocheck, set the goal in 2014: To run a marathon in all 50 states to help raise awareness and money to help cure the estimated 500,000 children that become blind each year.

At just 9 years old, Toocheck ran his first marathon with his dad. The pair would crisscross the world – passing penguins and whales in Alaska, braving the heat in Australia – while they ran marathons on the remaining six continents.

His efforts helped raise $42,000 to help needy children get jackets.

“When I completed that quest at the age of 11, everyone was asking me what I was going to do next,” Toocheck said.

RELATED: First paralyzed person will cross Marine Corps Marathon finish line

That’s when he decided to run in all 50 states to help people, many of whom live in third-world countries, beat blindness. Nick’s dad is an eye doctor.

“Since it’s something personal, it’s kind of in our family, it makes us try to push harder and you know, raise money for something that we really care about,” Toocheck said.

Toocheck and his dad have run in 42 states already. The Marine Corps Marathon will mark their fifth race this month alone.

“You know, I do back-to-back sometimes,” Toocheck said. “So when I wake up in the morning you know you’re in pain, I just think of the kids that I’m helping and that definitely pushed me to complete it.”

Toocheck expects to meet his goal of running in all 50 states when he races next July in San Francisco.

So far his and his dad's work raised a few thousand dollars for the Seva Foundation, the organization that makes a special effort to help kids get their sight back.

To donate to the organization, click here.

MORE: Marine Corps Marathon road closures