The potential of hand cutaneous vision: A study on groups of sighted individuals and two cases of blind adults

Recent research has uncovered photoreceptors in human skin akin to those found in the retina, suggesting the potential for color perception through tactile sensation. In addition, a study has demonstrated changes in brain waves in response to the skin’s perception of colors. Building on these findings, this study investigated whether two totally blind adults could acquire the ability to identify colors by touching cards after 1 month of home training. This followed a preliminary experiment that verified sighted individuals could improve their scores through 1 month of home training while blindfolded. Participant A, who is in their 50s and was sighted until age 11, showed improved tactile color perception after the training. In contrast, Participant B, blind since birth and in their 30s, did not show similar improvement but instead showed slight improvement. These results indicate that tactile color perception can develop even in totally blind adults, and furthermore suggest that acquisition is more advantageous with prior visual experience. This research underscores the potential for alternative pathways to color perception beyond traditional vision.