Hydrophobic hard intraocular lenses (IOL) and hydrophilic hard and soft IOLs were implanted in the eyes of 21 adult cats. During surgery, a 45-second purposeful contact was made between the lens surface and the cornea endothelium. The cats were followed for 6 weeks, sacrificed, and the corneas were examined by Scanning Electron Microscopy (SEM). The hydrophobic hard lenses produced permanent corneal edema and SEM revealed large areas of damaged endothelial cells. A slight cornea epithelial edema was evident in the first 2 weeks postoperative in eyes with hard hydrophilic lens implants. Soft lenses caused mild iritis and striate keratopathy that lasted from 2 to 6 weeks. SEM revealed numerous microvilli but no damage to the cell membranes. These results suggest that hydrophilic surfaces produce less endothelium damage. Whether the ocular inflammation caused by soft hydrophilic lenses is the result of inherent properties of the material or the result of material impurity needs further investigation.