A project offering free cataract surgery has helped more than 30,000 blind people regain their eyesight in the Tibet autonomous region.

For more than 20 years, the Regaining Eyesight Project initiated by the Tibet Development Fund has provided free cataract surgery in Tibet.

"I finally know what 'blue' looks like. It's great to be able to see the world," said Tudan Cering, a 7-year-old boy with congenital cataracts, who underwent free surgery two months ago in East China's Zhejiang province.