We describe the gravitational lens on a constant-curvature background by
using an optical constant-curvature (OCC) approach that allows to explicitly
take into account a global geometry of the background space. First, light rays
are curves in the space described by an optical metric. The OCC approach
focuses on the case that the optical metric for the background spacetime has a
constant curvature, for which the exact lens equation on an OCC background
[Phys. Rev. D 105, 084022 (2022)] can be used. As a concrete example, next we
discuss the gravitational lens in Mannheim-Kazanas (MK) solution, which include
Rindler and de Sitter terms. By fully taking into account a background
dependence of the light deflection, the deflection angle of light consistent
with the OCC approach is well defined at large distance. In the OCC approach,
finally, we examine the global behavior of the deflection angle and the
gravitational lens observables in the Weyl gravity.Comment: 11 pages, 4 figure