In her youth, there were few sports Chris Tan would not try her hand at.
Give her a pool and she would swim in it; put her on a track and she would jump - long or high, it mattered not.
From basketball to volleyball, she loved them all.
Until the day her world went almost completely dark when she was a teenager.
"I told myself that that was it," said Tan, who lost more than 90 per cent of her vision after being diagnosed with glaucoma. "At the time, nothing could motivate me to get back into sports."
How times have changed.
Last year, she discovered the Sports for the Blind programme and took up soundball - a variation of tennis using shorter rackets and sponge balls which rattle when they bounce.
Now 40 and a mother of two, the housewife will run the 21.1km half-marathon in Sunday's Standard Chartered Marathon Singapore - her second successive entry in the Republic's largest running event.
"I never thought I would be able to do all this," admitted Tan, who completed last year's 10km race in 1hr 20min.
But she is not alone. She is one of approximately 10 visually impaired runners taking part in this year's SCMS who will be accompanied on their journeys by volunteers from within the title sponsor's ranks.
Tethered together by nothing more than a shoestring-like rope, these sighted guides will serve as their partners' eyes - easing them around corners and keeping them clear of obstacles.
"With him, I know that I am well taken care of," Tan said of her guide, Standard Chartered managing director for corporate finance Ben Strickland.