  The angular diameter distance of lens, $D_{Aol}$, of strong gravitational
lensing systems has been claimed as a cosmic standard ruler. The first
measurements for this distance were recently obtained to two well-known
systems: B1608+656 and RXJ1131-1231. However, there is a range of possible
systematic uncertainties which must be addressed in order to turn these systems
into useful cosmic probes. In this paper, we confront $D_{Aol}$ with luminosity
distances of type Ia supernovae and angular diameter distances of galaxy
clusters to search for tensions between these cosmological measurements using
the cosmic distance duality relation. No tension was verified with the present
data, showing the robustness of the assumptions used to describe the lens
systems.
