(CNN) -- Imagine hurtling down a mountain at 60 miles an hour. Now imagine doing it virtually blind. For Kelly Gallagher, it's a thrilling reality. She might not quite reach the speeds of fully-sighted skiers -- Olympic champions can clock upwards of 90 mph -- but it is nonetheless a daunting prospect. It involves a great deal of trust in her guide, Charlotte Evans, a former skier herself who will play a key role in their chances of success at next month's Winter Paralympics in Sochi. "I don't really have depth perception, so snow in particular is quite difficult," Gallagher tells CNN's Human to Hero series. "I definitely need Charlotte to be able to help me ski."
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Kelly Gallagher and Charlotte Evans will be competing at the Sochi Winter Paralympics
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The skiers enter the Games in good form, claiming top spot in a recent super-combined race
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Gallagher is visually impaired and Evans became her guide after a serious knee injury
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Gallagher says of her native Northern Ireland: "We have hills but we don't have mountains."
It's then up to @placeholder to make adjustments as she's warned about a difficult patch, told to "tuck" or, conversely, drop speed.