Catching photons: Visible light, an amine reductant, and a [Ru(bpy)3]2+ photocatalyst can be used to mediate the addition of glycosyl halides into alkenes to synthesize important C-glycosides (see scheme). This method shows the growing potential of photocatalysis to effectively drive useful and difficult chemical transformations. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.