Human and rabbit corneas were stored at 4 degrees C in K-Sol with and without antioxidants (ascorbic acid, reduced glutathione, alpha-tocopherol, and retinol acetate) for two to three weeks. All the corneas were then examined visually and by scanning electron microscopy. They appeared clear and slightly oedematous. Scanning electron micrographs were used to grade corneal endothelial cell morphology in a masked manner in terms of cell shape, cell borders, cell swelling, and apical holes. Corneas stored in K-Sol without antioxidants showed changes in cell shape, cell borders, and apical holes. Human corneas showed more morphological changes than rabbit corneas. The results suggest that antioxidants in K-Sol have an important role in the preservation of endothelial cell morphology.