Sensors for the Visually Impaired

Abstract

In this chapter a survey of the background on visual impairment and blindness has been given. Common causes of visual impairment and statistical data have been presented in a short form. Of the wide variety of sensory aids, ultrasonic, optical, and other electronic sensors for mobility, orientation, and navigation have been discussed, in addition to sensory aids for communication and information. Sensors for mobility and orientation are considered as secondary travel aids and are used as a supplement to the traditional long cane or the guide dog. Among the sensory aids for communication and information, mostly closed circuit television systems and reading machines are in use today. A quick look into the relevant patent literature showed that almost all aspects of present sensory aids are covered by patents and patent applications. It is expected that in the near future further progress will be made with more sophisticated and miniaturized sensory aids for the visually impaired. A real technological challenge will be the realization of retina implants. If this approach works successfully, there is a good chance of restoring vision for blind people.