The present study: (a) determined the effects of both pre- and early postnatal androgen hormonal manipulation on retinal thickness, (b) examined the presence of the aromatase enzyme by immunocytochemistry in retinal tissue and (c) quantified aromatase activity in the rat retina. The results suggest that retinal thickness is influenced by perinatal hormone manipulation via aromatizable androgens that have implications for the sex differences seen in visual information processing and performance.