  Ray optics is a useful tool even in the regime where, actually, full
wave-calculations would be appropriate. However, wave-inspired adjustments are
needed to ensure the accuracy of ray-based predictions. These corrections are
known as the Goos-H\"anchen shift, a lateral shift along the interface, and the
Fresnel filtering effect, an angular shift, that violates Snell's law and the
principle of ray-path reversibility. Whereas they are well established at
planar interfaces, an accurate description of microlasers and other microoptics
devices requires their precise knowledge at the curved boundaries
characteristic for these devices. Here, we present analytical and numerical
results that highlight the role of boundary curvature and show the clear
deviations from the planar case. We introduce an intuitive picture that allows
for a straightforward understanding why Fresnel filtering grows considerably
with curvature whereas the Goos-H\"anchen shift becomes less important.
