Photos: Equinox marathoner raises awareness for Usher syndrome

Fairbanks' Equinox Marathon is widely regarded as one of the most difficult marathons in the nation. Runners endure an 1,800 feet ascent up Ester Dome, racing through wooded trails laced with tree roots and ruts, and over gravel roads before braving a steep descent – sometimes, in the snow.

Think that's hard enough? Now, imagine running it blind.

Brian Switzer will do exactly that on Saturday, when he runs the trail's 26.2 miles in support of the Usher Syndrome Coalition's campaign to "Own the Equinox," and raise awareness for the debilitating disorder.

READ MORE: Blind Fairbanks Equinox marathoner to shine light on rare genetic disorder?