  Recently Kastner has analyzed the issue of visibility in a modified two-slit
experiment carried out by Afshar et al, which has been a subject of much
debate. Kastner describes a thought experiment which is claimed to show
interference with hundred percent visibility and also an "apparent" which-slit
information. We argue that this thought experiment does not show interference
at all, and is thus not applicable to the Afshar experiment.
