Leaving aside the issue of mental effects, how would bending light waves make an object invisible

Sue Storm, a member of the Fantastic Four, has the ability to not only make herself invisible, but also objects around her invisible. She supposedly does this feat by mentally bending all wavelengths of light in the vicinity around herself or the target in question. Leaving aside the issue of mental effects, how would bending light waves make an object invisible? And if one were invisible, how would you then be able to see? Make whatever assumptions you need in your discussion response.