Epidermal Growth Factor is a polypeptide isolated from mouse submaxillary glands and evaluated by histological studies. The healing of 7.3 mm diameter central corneal epithelial wounds after treatment with epidermal Growth Factor was measured by standardized photography. The results suggest that topically-administrated Epidermal Growth Factor, at a frequency of four (p less than 0.02) and six (p less than 0.001) times daily, significantly increases the corneal epithelial healing rate compared to the vehicle control. Histological examination of the control eyes enucleated after seven days of treatment showed an epithelium four to five layers in thickness. The basal cells had a round shape and round, centrally-positioned nuclei. The Epidermal Growth Factor treated group (six times daily) had an epithelial thickness of five to six layers. The basal cells were taller and more tightly-packed with oval nuclei oriented towards the apex of the cell.