Abstract : Small ion-irradiation-induced defects can dramatically alter material properties and speed up degradation. Unfortunately, most of the defects irradiation creates are below the visibility limit of state-of-the-art microscopy. As such, our understanding of their impact is largely based on simulations with major unknowns. Here we present a novel x-ray crystalline microscopy approach, able to image with high sensitivity, nano-scale 3D resolution and extended field of view, the lattice strains and tilts in crystalline materials. Using this enhanced Bragg ptychography tool, we study the damage helium-ion-irradiation produces in tungsten, revealing a series of crystalline details in the 3D sample. Our results show that few atom-large ‘invisible’ defects are likely isotropic in orientation and homogeneously distributed. No defect-denuded region is observed close to the grain boundary. These results open up exciting perspectives for the modelling of irradiation damage and the detailed analysis of crystalline properties in complex materials.