We introduce and develop a new concept, the refraction holodiagram (RHD), in analogy to the holodiagram (HD) developed by Neils Abramson. The main difference between both concepts resides on the elements used to change the light propagation direction from one focus to the other one. In the present case they are nominally refractive elements instead of reflective ones. We present their surface solutions, which are Cartesian ovals - instead of ellipsoids as it is the case in the HD. We also discuss some applications of the RHD to holography and interferometry and generate moiré patterns which reproduce RHDs.