Mantra CEO Sam Waldo promotes the latest line of sunglasses and the “Buy One, Give One” purchase model, in Beijing. [Photo provided to China Daily]

Some had misplaced their frames, others felt that their prescription was uncomfortable and a few had ceased wearing them because their parents had told them to, preferring them instead to massage their eyes and stare at green objects to "cure" their nearsightedness.

"We realized education needed to be a much bigger part of our organization," said Shirman, speaking to City Weekend.

That year, EIS reached out to Shirman's growing network of TFC teachers and recruited them as "sight leaders" to educate students about myopia and create a positive culture around glasses.

As the scope of their operations increased and more donations began flooding in, Shirman - who had since moved back to Boston after a two year stint teaching in Yunnan - and Waldo were able to start running EIS full time. Their first task: to navigate their way through the legal red tape and paperwork necessary to allow their nonprofit to become a legitimate charitable organization.

With the necessary documentation and approvals in place, the team managed to secure a partnership with influential nonprofit China Children Teenager's Foundation (CCTF). This allowed EIS to raise funds via the electronic wallets of millions of Chinese on WeChat.

Their first WeChat-oriented fundraiser in 2015 generated almost 100,000 yuan in just a month. The sum was far more than previous fundraising efforts had mustered, since they had been heavily reliant on the personal networks of EIS staff members in the US.

But EIS needed to raise much more money to achieve its lofty, but by no means unattainable goal of providing 35,000 screenings and 7,000 pairs of glasses by the end of the 2015 school year.

After suffering a setback when a Chengdu company pulled out of a donation pledge, Shirman and Waldo decided it was time to make EIS more sustainable. EIS's profit-making arm of the organization, Mantra - a line of fashionable Yunnan-themed glasses and sunglasses made with "all American materials" – was born.

The social enterprise's motto encourages people to "Look Good, Do Good," and promises that for every pair of glasses bought, it will donate one prescription pair to children in need through EIS. Mantra is similarly modeled to TOMS shoes, which adopts a "Buy One, Give One" business model.

"Our ‘Buy One, Give One' concept is simple: for every pair of sunglasses we sell, we donate a pair of prescription glasses to a student in need in rural Yunnan," said Waldo.

Each pair of eyewear ordered from Mantra comes with a unique QR code inside the case, which can be used to track donations to EIS. Customers are able to see exactly where their donation money goes through a backstage research website linked with Mantra's WeChat account.

"100% of the money that goes to EIS from Mantra is directly used to get glasses for needy students," said Shirman. "We tell our customers where their money went and how it was spent, and what students received glasses and when."

Mantra has so far sold thousands of glasses, with as many bespoke prescription pairs being donated in the surrounding areas of Lincang, Baoshan and Shangri-La in Yunnan province.

"We're also creating this together with our local designers, bringing unique local colors, patterns and art to the fore of our design," said Waldo.