Although most studies of hormonal modulation of anuran behavior have focused on acoustic communication, recently more studies have addressed the modulation of vision, in general, and the retina, in particular. The predominance of auditory work stems from the fact that most anurans are nocturnal and consequently use elaborate acoustic signaling. Over the past decade, however, work has shown that visual cues are also used in mating decisions, even under nocturnal conditions. This study examined how experimentally induced reproductive state affects such low-light visual processing. To do this, we performed electroretinograms (ERGs) to determine the retinal sensitivity of túngara frogs (Physalaemus pustulosus), a neotropical species whose mating behavior includes visual cues. ERGs were recorded under scotopic and photopic conditions in frogs that were either non-reproductive or hormone-treated with human chorionic gonadotropin (hCG) prior to testing. We also took optical measurements to determine how túngara frog eye and retina morphology related to ERG sensitivity. As expected, we found that both sexes display higher visual sensitivity under scotopic compared to photopic conditions. However, hormone injections significantly lowered scotopic retinal thresholds of females. This change enabled full use of predicted optical sensitivity and suggested modulatory mechanisms specific to mate searching conditions and rod-based vision. These results support the hypothesis that hormonal modulation of neural mechanisms, such as those mediating visually guided reproductive behavior in this species, include sensory organs: the retina.