By Paolo Sandoval There’s no denying the synergy between Canadian label Reigning Champ and the running gurus at District Vision. The pair, who originally teamed up in 2019 for an elegant “Radical Retreat” capsule, are back with a triumvirate of sleek eyewear, centered around their shared ethos of quality and performance. Unlike many of the athleisure and sports-forward brands that peddle flashy, expensive and poorly designed apparel, Reigning Champ and District Vision both tout a refined collection of elite (and often subtle) gear, and their newest joint endeavor proves to be no different. Ins…