The clinical and pathologic features of two congenital tumors are delineated and discussed. Each tumor is composed of glial and neuronal elements and appears to arise within colobomatous defects in the ciliary body, iris, and retina. These benign tumors resemble well-differentiated mature brain tissue, and are believed to represent choristomatous malformations developed from divergent differentiation of the neuroepithelial cells at the advancing margin of the invaginated optic cup.