2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/8943We evaluate the effect of small scale inhomogeneities on large scale observations within the statistics of gravitationally lensed quasars. At this aim, we consider a cosmological model whose large scale properties (dynamics, matter distribution) are the same as in Friedmann-Lemaitre models, but whose matter distribution is locally inhomogeneous. We use the well known Dyer-Roder distances to allow a simple analytical expression of the optical depth, and pay particular attention on the different role played by the different notions of distances (filled beam angular diameter distance and Dyer-Roder distances) when calculating this quantity, following the prescription from Ehlers & Schneider for a coherent formalism. We find that the expected number of gravitationally lensed quasars is a decreasing function of the clumpiness parameter.11 pages, 9 figures. MNRAS, in pressAstrophysicstext