  We extend the ideas of the recently proposed perfect lens [J.B. Pendry, Phys.
Rev. Lett. {\bf 85}, 3966 (2000)] to an alternative structure. We show that a
slab of a medium with negative refractive index bounded by media of different
positive refractive index also amplifies evanescent waves and can act as a
near-perfect lens. We examine the role of the surface states in the
amplification of the evanescent waves. The image resolution obtained by this
asymmetric lens is more robust against the effects of absorption in the lens.
In particular, we study the case of a slab of silver, which has negative
dielectric constant, with air on one side and other media such as glass or GaAs
on the other side as an `asymmetric' lossy near-perfect lens for P-polarized
waves. It is found that retardation has an adverse effect on the imaging due to
the positive magnetic permeability of silver, but we conclude that
subwavelength image resolution is possible inspite of it.
