In a light microscopic study of the macula of 104 human eyes obtained at necropsy of patients aged 3 to 96 we found: (1) Displacement of nuclei from the outer nuclear layer into the outer plexiform layer occurred in small numbers early in life and markedly increased after age 30. (2) Displacement of nuclei from the outer nuclear layer to the layer of rods and cones was rare in early life but increased considerably after age 40. (3) Displacement of nuclei is probably secondary to shrinkage of their attached fibres and is associated with aging. (4) Displaced nuclei apparently undergo changes in size, shape, and chromatin content and may go on to necrosis. (5) Twenty-four of the 104 eyes studied had an obvious reduction in the numbers of nuclei in the outer nuclear layer and their photoreceptors in the macular zone. All were in eyes from patients over age 40. No concomitant defect was found in the subjacent pigment epithelium, Bruch's membrane, or the choriocapillaris. The loss of nuclei of the outer nuclear layer appears to be a primary retinal disorder associated with aging.