After a routine health check-up in primary school, 10-year-old Rayner Teo was prescribed reading glasses. But by the time he picked up his glasses, he could not see clearly even with them on.

A battery of tests at Singapore National Eye Centre later, he was diagnosed with Leber’s Hereditary Optic Neuropathy (LHON). The disease that causes bilateral, painless, subacute visual loss in young adults is four times more likely to affect men than women.

Mr Teo, now 24, has limited and blurry vision. He cannot even see the menu at food stalls clearly. “In upper primary, I faced curious classmates as well as those who called me names,” he told TNP….