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Head-Mounted Display Systems as Visual Aids for the Visually Impaired:A Survey

According to the World Health Organization, roughly 40 million people around the world are blind. Moreover 250 million people are defined as visually impaired. These numbers are expected to increase as the populations of Europe and other countries age. These patients can take advantage of evolving high-technology and can be helped not only by the conventional optic aids (optical glasses, white canes etc.) but also by a new generation of head-mounted display (HMD) devices. In this paper we make a brief review of the first attempts of using electronic glasses to enhance the environment of the user and a more detailed report on HMD systems that use virtual reality (VR) or/and augmented reality (AR) that are used as visual aids for the visually impaired and are on the marketplace nowadays. We discuss their technical features and we present clinical trials using these devices and their results.