Nutritional deficiencies in relation to disorders of the eye have been described by many workers.* Cataracts in rats fed a riboflavin-deficient diet were described in 1931 by Day, Langston, and O'Brien.3 Curtis and co-workers,4 in 1932, produced cataracts in rats with a tryptophan-deficient diet. As far as we know, these are the only true primary deficiencies that have resulted in cataract formation. The relation of vitamin E to retrolental fibroplasia was suggested by Owens and Owens5 in 1939. Callison and Orent-Keiles,6 in 1951, observed a lesion in embryos from rats fed vitamin E-deficient diets which suggested retrolental fibroplasia. Cataracts were described in 1954 by Ferguson, Atkinson, and Couch7 in turkey embryos obtained from hens fed a practical-type diet low in vitamin E. A similar lesion has occurred in turkey embryos obtained from hens fed a synthetictype diet deficient in vitamin E. The pathologic changes in