The effect of short-term light deprivation on tactile spatial acuity was evaluated by asking 28 adult humans to perform a grating orientation task. The 14 subjects who were kept for 90 minutes in complete dark showed, immediately after deprivation, a reversible improvement of tactile spatial acuity. No acuity change was observed in the 14 nondeprived subjects. Results indicate that even a short-term visual deprivation may disclose highly dynamic plastic interactions between visual and tactile systems