Mark Pollock was well known among Ireland's outdoor adventurers thanks to a love of marathon running and his participation in endurance events. That he was permanently blind made him stand out among the country's adrenaline junkies. He was the first fully unsighted athlete to complete the arduous Race to the South Pole competition and he happily participated in an extreme running challenge in the Gobi Desert.
The Belfast man went blind at the age of 22 when his retina became detached. He had lost the sight in one eye at just five years of age - also due to a weak retina attachment. And while he took a long time to get used to having no sight, he proved to be a highly resilient figure with an infectious joie de vivre. "I had got used to being blind," he says today. "And life was good - I was achieving things I probably never would have done had I not lost my sight."
The summer of 2010 was set to be the happiest of his life, as he was due to marry his fiancee, Simone George, at the end of July. "I've never seen her," he says, "but people tell me she is beautiful. I have an idea about what she looks like and I'd love to see how the Simone in my mind compares to the reality."
But the pair were not to marry because misfortune struck Mark once more. Just four weeks before their wedding date in Kilkenny, Mark and some friends travelled to Henley on the banks of the Thames for its world-famous Regatta. What should have been a happy lads' weekend for this keen rower ended in tragedy when he fell through an upstairs window of a house and toppled 25 feet to the pavement below.
After having had to adjust to the horrors of going blind, the Belfast man now had to face up to the grim reality that he was paralysed from the waist down. "Of course I questioned why this had happened to me," he says. "It's difficult enough to be paralysed, but having to cope with that while being completely blind made me feel helpless for the future."
He says he cried every day for the first three months and in those especially dark moments he thought it might be more preferable for him not to be alive at all. But that extraordinary resilience in the face of adversity ensured that he wasn't going to give up without a fight. "The hardest thing was losing my independence," he says. "I had that, to a large degree, with blindness. But now I needed help to do so many of the things I had taken for granted before."
Simone has stood by his side since then and Mark pays tribute to her: "She has been hugely important to me. She was in hospital with me every day for the guts of a year. She is the most empathetic, caring person you could meet."
Paralysis doesn't just mean an inability to walk - it also has a significant impact on bodily function and sexual response. "There can be 15 or 20 secondary issues that people might not think of when they think of paralysis," Mark says. "It's not just about greatly reduced mobility. There's also the huge financial burden to worry about and the fact that 75pc of paralysed people are unable to work afterwards."
Mark has been through extensive bouts of rehab and can walk with mechanical aids, but hopes that one day he will be able to walk unassisted. "I want to do everything I can to raise awareness of paralysis and money for a cure," he says.
To that end, he has become a full-time campaigner on paralysis and his Run in the Dark fundraising initiative, now in its fourth year, will see more than 15,000 people running the streets of various cities tonight - including Dublin and Cork - with 'pop-up' events happening as far afield as Sydney.
Meanwhile, Mark is the subject of an acclaimed feature-length documentary now showing at selected cinemas nationwide. Unbreakable, which was directed by an old Trinity College friend, takes an unflinching look at his world since the fall and about how his loved ones, especially Simone, have sacrificed so much of themselves in an effort to make his life as worthwhile as possible.
"He's a very charismatic guy and I hope that comes across in the film," director Ross Whitaker says. "He was a lot of fun in college and was very popular. Of course, none of us were to know what life was to throw at Mark, but you always felt that he was the guy who would have been best equipped to deal with something like this."
Ross hopes that Mark's openess in the film will give people a sense of how debilitating life can be for those coping with paralysis and he points out that since the death of Superman actor Christopher Reeve, the condition isn't in the public eye as much as it might be.
"Mark is the most remarkable man," he says, "but the Unbreakable title is not just a reference to his character. It's about Simone too and her enormous contribution to his rehabilitation."
The Life Style Sports Run in the Dark event takes place at 8pm tonight in Dublin and other Irish cities tonight. See runinthedark.org