Spatially resolved polarization properties of in vitro mammalian corneas have been studied by using a Mueller-matrix imaging polarimeter in transmission mode. Sixteen images corresponding to independent combinations of polarization states in the illumination and analyzing pathways are recorded. Spatially resolved Mueller matrices of the samples are calculated from them. Results show that the birefringence of the cornea is almost linear. Although the magnitude of retardation depends on the sample, it is approximately constant at the center and increases towards the periphery. Dichroism and polarizing power are negligible. Maps of the degree of polarization indicate that the cornea basically does not depolarize the totally polarized incident light. q 2001 The College of Optometrists. Published by Elsevier Science Ltd. All rights reserved.