Design and evaluation of a wearable assistive technology for hemianopic stroke patients

More than one million people in the US suffer from hemianopia, which blinds the vision in one half of the peripheral vision in both eyes. Patients with hemianopia are often not aware of what they cannot see and frequently bump into walls, trip over objects, or walk into people on the side where the peripheral vision is diminished. In this study, we present an augmented reality based assistive technology that expands the peripheral vision of hemianopic patients at all distances. In a pilot trial, we evaluate the utility of this assistive technology for ten hemianopic patients. We measure and compare outcomes related to target identification and visual search in the participants. Improvements in target identification are noted in all participants ranging from 18% to 72%. Similarly, all the participants benefit from the assistive technology in performing a visual search task with an average increase of 24% in the number of successful searches compared to unaided trials. The proposed technology is the first instance of an electronic vision enhancement tool for patients with hemianopia and is expected to maximize the residual vision and quality of life in this growing, yet largely overlooked population.