Irvine, California (CNN) -- It wasn't until Yash Gupta broke his glasses in taekwondo practice that he realized just how much he relied on them.
His prescription was so high that he had to wait a week to get a new pair.
For Gupta, then a high school freshman, those seven days were a blur. Literally.
"I just couldn't see anything," said Gupta, now 17. "I couldn't see in the classroom; I would get easily distracted. ... Just basic stuff I used to do every day, I couldn't do."
Gupta's eyes were also opened to a much larger problem. He saw on the Internet that more than 12 million children worldwide don't have the corrective eyewear they need (PDF).
"It's just a total disadvantage for them, because (if) you can't see anything ... you definitely can't make the most of the education you're being given," he said. "It would be impossible for them to fully achieve their potential.
"I had this problem for one week, but these kids have these problems for their whole lives."
So at just 14, Gupta started Sight Learning, an organization that collects used eyeglasses from optometrists and donates them to organizations that can deliver them to children in need.
Since 2011, Gupta has donated 9,500 pairs of glasses, worth nearly $500,000, to young people in Haiti, Honduras, India and Mexico.
For Gupta, who has worn glasses since he was 5 years old, the idea of repurposing old eyewear made sense. Most of his family members wear glasses, and just searching his own home yielded instant results.
"I found 10 to 15 pairs just lying around the house in random drawers," Gupta said.
He realized those glasses alone could help 10 or 15 children. So, with help from his father, Gupta set up his organization and approached local optometrists, who agreed to put out drop boxes where patients could donate their used eyeglasses after getting a new pair.
"That first interaction was really promising for me," he said. "Some of (the optometrists) already had pairs of glasses that they had just accumulated over the years that they didn't know what to do with."
In the past three years, Gupta has gone on numerous trips to India and Mexico, where he not only provides glasses but also assists the doctors and volunteers at eye clinics.
Those who work with him see his age as an asset.
"He works hard and has great initiative, but more importantly, he brings such great energy -- and that sets the tone for everyone," said Dr. Greg Pearl, president of the California chapter of Volunteer Optometric Services to Humanity.
Gupta says that being in the field is the best part of his work.
"That dazed look the first time (children) get glasses, and just seeing that turn into joy and happiness ... it's just really inspiring," he said.
Gupta knows that the glasses he's providing can make a big impact.
"A lot of times, these families are in poverty," he said. "With a good education, you know, they can get a good job and get a good career."
Helping others motivates Gupta, whose family immigrated to the United States from India when he was just 1 year old.
"We had a really tough time adapting," Gupta recalled. "I (am) sympathetic to people who (are) struggling."
Gupta, a senior in high school, helps fund his work by tutoring younger students after school, and he spends about 20 hours a week collecting and shipping the glasses. He plans to continue when he gets to college, and he has his eye on expanding into new territory.
"Right now, we're partnered with organizations that do international work. But in the future, I'd like to bring this service to inner cities in the U.S.," he said.
Gupta has gotten a lot of attention for his work, including being honored at a White House event in July. But he says other people his age are also finding ways to give back.
"I think there's a misconception with our generation," he said. "Many of my friends are doing things to improve their communities.
"Kids are passionate and can make a difference. It's just a matter of finding out what you care about and focusing on that."
Want to get involved? Check out the Sight Learning website to see how to help.