  We explore the scale and angular dependence of the cosmic shear three-point
correlation function. The shear field is found to have a much more complex
three-point function than the convergence field, but it also exhibits specific
motifs which draw signatures of gravitational lensing. Exact shear patterns are
inferred analytically for some geometrical shear triplets configurations, when
simple interpretations can be derived. A more complete description of their
geometrical properties has then been carried out from ray-tracing numerical
simulations and simple models. These patterns reveal typical features that can
be utilized for non-gaussian signal detection in cosmic shear surveys. We test
the robustness of these properties against complex noise statistics and
non-trivial survey topologies. From these conclusive checks, we predict that
the VIRMOS-DESCART survey should allow a detection of a non-gaussian signal
with a comfortable significance for a low matter density Universe.
