Protein deficiency is one of the major morbid nutritional disorders of the developing world. Increased incidence of infection in a protein-deficient state is well documented in the literature. Structural alterations produced by isolated protein deficiency on the cornea are not clear hitherto. In this investigation, it has been shown that protein deficiency in rats results in thinning of the corneal epithelial cell layers and oedema of the epithelial, stromal and endothelial cells. The pathomechanisms are discussed.