Tunnel vision is a visual impairment where only central vision remains functional. A restricted field of view gives rise to major difficulties in everyday life and especially to find specific objects within the environment. Communicating the location of specific targets with private and non-intrusive tactile cues may facilitate the behavior of visual search. Here we designed four tactile techniques that allow localizing specific points in space. Tactile stimulations were either single stimuli or trains of pulses rendered in a Cartesian or a Polar coordinate system. The techniques were compared within a head pointing task. The most efficient one was then evaluated during a visual search task in a complex virtual environment. The evaluation involved ten subjects with a simulated restrictive field of view (10°), and one visually impaired subject with a tunnel vision due to glaucoma. During this evaluation, our tactile assistive device significantly improved the visual search efficiency with a factor of three. The device could easily be integrated within smart glasses and help to detect targets of interest either on demand or suggested by the device itself (e.g. potential obstacles), facilitating visual search and spatial perception of the environment.
['Damien Appert', 'Damien Camors', 'Jean-Baptiste Durand', 'Christophe Jouffrais']
Tactile cues for improving target localization in subjects with tunnel vision