Deformation of amorphous, glassy polycarbonate (PC) is characterised over a wide range of length-scales using spatially-resolved wide angle X-ray scattering (WAXS) with simultaneous digital image correlation and in-situ uni-axial loading. Novel observations are presented on the correlation of the evolution of the molecular structure linked to the relevant local macroscopic measures of strain as the sample deforms. This provides new insights into the mechanisms of deformation in amorphous, glassy polymers. Strains and evolving anisotropy are observed, and quantified, at different length scales identified from the WAXS measurements connected to inter-and intramolecular structures. The inter-molecular structures show permanent deformations in the form of unrecoverable stretches and reorientations, whilst intramolecular structures show recoverable strains and unrecoverable reorientations. Such insights pave the way for development of enhanced constitutive models for amorphous glassy polymers with a correct micro-mechanical basis and calibrated evolution of anisotropy. (C) 2015 Elsevier Ltd. All rights reserved.