During development, the organization of the brain’s underlying circuitry is shaped by sensory experience. However, how the adult brain reorganizes remains much less understood. Here, we performed a longitudinal BOLD-fMRI study assessing plasticity in the adult rat brain using a chronic visual deprivation model and a novel set-up for mapping detailed visual responses. We show that dark rearing (DR) boosts neural responses to visual stimuli but delays retinotopic and spatial frequency (SF) specialization in the visual pathway. Our findings suggest that DR shifts the stability/plasticity balance and that fMRI can map dynamic processes in the visual system.