  We study flows and interface deformations produced by the scattering of a
laser beam propagating through non-absorbing turbid fluids. Light scattering
produces a force density resulting from the transfer of linear momentum from
the laser to the scatterers. The flow induced in the direction of the beam
propagation, called 'optical streaming', is also able to deform the interface
separating the two liquid phases and to produce wide humps. The viscous flow
taking place in these two liquid layers is solved analytically, in one of the
two liquid layers with a stream function formulation, as well as numerically in
both fluids using a boundary integral element method. Quantitative comparisons
are shown between the numerical and analytical flow patterns. Moreover, we
present predictive simulations regarding the effects of the geometry, of the
scattering strength and of the viscosities, on both the flow pattern and the
deformation of the interface. Finally, theoretical arguments are put forth to
explain the robustness of the emergence of secondary flows in a two-layer fluid
system.
