  The non-magnetic loss material has been proposed (2011 New J. Phys. 13
023038) to mimic a passive perfect drain in the Maxwell's fish eye lens (MFL).
In this comment, we argue that this passive medium can only be treated as a
perfect absorber which can totally absorb all incident radiation without
scattering by it, but it cannot mimic a perfect focusing point. As a result,
this passive medium cannot help to achieve a perfect focusing in MFL.
