This paper describes results of experimental studies on radiation defects in nominally pure single crystals of corundum in two initial states: α-Al2O3 with an unperturbed lattice and α-Al2O3:C with a high concentration of anion vacancies. Defects were identified from optical absorption spectra, ionoluminescence, pulsed cathodoluminescence and photoluminescence spectra. It is shown that mostly color centers of the F- and F+-types are formed in the α-Al2O3 lattice under irradiation with 5,7 MeV protons. © 2009 Elsevier Ltd. All rights reserved.