Individuals with complete or partial loss of vision or hearing have a reduction of sensory input that affects their interaction with the environment. Approximately 3.5–6 million people have vision loss and 8 million have hearing loss. Different diseases and pathologies give rise to different forms of functional limitations. Individuals with loss of vision or hearing improve function through the use of sensory aids as a supplement to or a substitute for seeing or hearing in order to participate in society and to perform activities of daily living. Sensory aids range from individual medical and assistive devices to technologies that enhance the accessibility of the natural, built, transportation, and information/communications environments. Some individuals with vision loss may also use readers and those with hearing loss may use sign language interpreters to access information. Research and development, commercialization, and public support for purchase of individual aids and change in environmental accessibility have been stimulated or mandated by public laws and regulations such as those related to the Americans with Disabilities Act of 1990. Using a universal design strategy, some aids are designed into mainstream products and environments, as is the case of the decoder chip that produces captioning on the screen of a television set. Universally designed products have spilled over from special interest markets such as deaf and hard of hearing users of captioning to mainstream markets in locations with loud background noise such as health clubs and bars. Although the history of the development of sensory aids is hundreds of years old, opportunities and challenges have proliferated with the development of computing and communications technology. Throughout history, individuals with vision loss and individuals with hearing loss have challenged engineers, and clinicians, and architects with their different medical, functional, and environmental problems.