Many R2-R5 neurons fail to terminate in the lamina and instead project into the medulla in mutant larvae. Small areas of the lamina plexus remain and are separated by large gaps. Thicker axon bundles than normal are found in the medulla. Lamina neurons form columns largely as in wild type in mutants. In the central photoreceptor cell projection field of mutant eye-brain complexes, the number of glial cells is reduced. Instead of three glial cells per column (the epithelial, marginal and medulla glial cells), often only one or two cells are present. Satellite glial cells appear to develop normally. Glial cells found in the eye imaginal disc, optic stalk and entrance to the optic lobe also appear normal. An increased number of glial cells accumulate at the dorsal and ventral margins of the photoreceptor cell projection field in mutants.