So far, it has helped 2,000 people regain their eyesight. The facility was the work of two volunteers, Hongkonger Joyce Wong Hoi-yan and her African husband Henri Samoutou.
Wong, 35, grew up in Hong Kong's tenement houses, graduated from Diocesan Girls' School and studied medicine at the University of Edinburgh.
Her path took a turn in 2000 when she decided to volunteer at a non-profit hospital in Gabon funded by the Christian Blind Mission. There, she met Samoutou, one of the country's first senior ophthalmic technicians. The two tied the knot four years later. The couple spent the first two years of their marriage in Britain, but did not forget Gabon.
The poor country on the west coast of Africa lies close to the equator. As with most people who live on the equator, the Gabonese are exposed to high levels of ultraviolent radiation every day. Many develop cataracts, in which the lens of the eye clouds up affecting their vision. Some lose vision entirely. Cataracts can be treated, but before 2006, many in Gabon just could not afford it.
The plight of the blind is particularly close to Samoutou's heart. "His father was blinded when chips of wood flew into his eyes," Wong says. "The local practitioner did not have the medicine or expertise to help. There was nothing he could do."
According to the World Health Organisation, four in five people who are blind do not have to be. Cataracts, river blindness (caused by a parasite) and trachoma (a bacterial infection) can be prevented or treated. Delayed treatment is the main factor of impaired eyesight.
In 2006, Samoutou and Wong, by then the parents of a baby girl, returned to Gabon with their daughter to build an eye clinic in Bongolo Hospital in Lebamba, making surgery affordable and accessible. A cataract operation there costs HK$625 - 10 times less than ophthalmologists in the capital of Libreville were charging.
Despite long queues, muddy roads and trips on overloaded vehicles, patients came to the clinic in droves. On the busiest day, the pair dealt with more than 100 patients. The worst case they saw was an elderly man who had been blind for 27 years.
But Wong says all the effort and frustration was worthwhile when she saw patients' excited faces as she removed their eye patches after operations. "The first thing one patient said to his wife whom he hadn't seen for 20 years was 'You have aged'," Wong says, laughing.
"I remember how she dragged him outside the clinic after check-ups and pointed at the car window, saying, 'Look at yourself. You've aged too.' It was hilarious, yet moving."
In two years of work, the couple operated on about 2,000 patients. Nine out of 10 came from the capital, but some even arrived from other countries. The couple returned to the UK in 2008 but are now set to move on to Congo-Brazzaville after launching New Sight (www.samoutou.com), a project to establish the country's first eye clinic.
They have already raised two-thirds of the HK$1.5 million start-up cost. In the next five years, they need to raise an additional HK$7million.
Wong says the Congo project will be a tougher challenge than their work in Gabon because the country is even poorer and more remote. They will also be towing along three young children.
"It's crazy to go and work in Africa," Wong says. "But it would be even crazier if we didn't."