In eyes with experimental retinal detachment, pigment epithelial cells and glial cells may form membranes on all available surfaces. In the subretinal space -- where normally no vitreous collagen is found -- variable amounts of collagen were detected in the intercellular space of these membranes. It is therefore concluded that retinal pigment epithelial cells and retinal glial cells are both capable of producing collagen. The type of collagen produced is indistinguishable from vitreous collagen.