How do you perceive the world? When someone asks this question, the simplest and most logical answer might be “through the information coming from our senses”. Since ancient times, numerous theories have emerged regarding the role of the senses and the perception of reality. It should come as no surprise how traumatic the loss of one or more sensory modalities can be for our life experience. The aim of this book is to assist those who have suffered such trauma by leveraging one of our primary intrinsic recovery mechanisms for sensory loss: neural plasticity, through the use of wearable haptic systems. This first chapter aims to present a concise overview of the theory of perception through the ages, explore how our bodies respond to sensory loss via neural plasticity, and discuss the related haptic interfaces designed to address these issues. Special attention is given to two disabilities intensively explored in the state of the art: blindness and upper limb loss.