The dominance of vision is so strong in sighted people that touch is sometimes considered as a minor perceptual modality. However, touch is a powerful tool which contributes significantly to our knowledge on space and objects. Its intensive use by blind people allows them to reach the same levels of knowledge and cognition as their sighted peers. In this book, specialized researchers present the recent state of knowledge about the cognitive functioning of touch. After an analysis of the neurophysiology and neuropsychology of touch, exploratory manual behaviours, intramodal haptic (tactual-kinesthetic) abilities and cross-modal visual-tactual coordination are examined in infants, children and adults, and in non-human primates. These studies concern both sighted and blind persons in order to know whether early visual deprivation modifies the modes of processing space and objects. The last section is devoted to the technical devices favouring the school and social integration of the young blind: Braille reading, use of raised maps and drawings, "sensory substitution" displays, and new technologies of communication adapted for the blind.