Four hospital trains will soon leave Beijing on an eight-month mission to help thousands of people around China see again.

The rainbow-colored trains, carrying high-tech surgical equipment and experienced doctors, aim to provide free cataract surgery to 12,000 people.

They will call at nine cities this year, starting at Fuyang in Anhui province before moving on to Luoyang in Henan province and Anshun in Guizhou province.

Supported by the Chinese Foundation for Lifeline Express, the trains are each equipped with a surgery room, two bathrooms and a recovery carriage for 40 patients.

Nellie Fong, founder of the NGO, said the trains were not only on a mission to restore sight, but also the hope of better living conditions through improved opportunities.

According to Fong, the trains have traveled to 151 cities since 1997 and provided free cataract surgery to more than 170,000 people in China's remotest areas.

The NGO has also built 62 permanent cataract medical centers, providing training to doctors from local hospitals on the treatment of common eye diseases.

Another six such medical centers will be built this year, offering long-term medical assistance to low-income patients, Fong said.