Diosmin significantly decreases the malondialdehyde (MDA) levels and increases the activities of total-superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in the retina of rats compare with the ischemia group (P<0.05), and suppresses the ischemia/reperfusion (I/R)-induced reduction in the a- and b-wave amplitudes of the electroretinograms (ERGs) (P<0.05). The thickness of the entire retina, inner nuclear layer, inner plexiform layer, and outer retinal layer and the number of cells in the ganglion cell layer are significantly less after I/R injury (P<0.05), and Diosmin remarkably ameliorates these changes on retinal morphology. Diosmin also attenuates the I/R-induced loss of retinal ganglion cells (RGCs) of the rat retina (P<0.05).