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We investigate wave propagation in curved, thin elastic waveguides, where curvature is shown to be equivalent to a spatially modulated refractive index. We establish this relationship within a theoretical framework that leverages non-Euclidean transformations. Theoretical predictions illustrate how curved profiles can be designed to manipulate wave trajectories in analogy with geometrical optics principles. Experiments on 3D printed curved membranes confirm the theoretical predictions, and suggest curvature as a viable approach for guiding, focusing and steering of elastic waves.