[TA] (1) a layer of white matter interspersed with nerve-cell bodies, immediately below the superficial gray layer of the superior colliculus, composed of myelinated fibers originating in the retina and striate cortex; (2) a rarely used term to describe the inner layer of the retina, consisting of the fibers originating from the cells of the ganglionic layer of the retina; in their further course these fibers combine to form the optic nerve. SYN: stratum opticum [TA].