Retinal prostheses, which restore partial vision to patients
blinded by outer retinal degeneration, are currently in clinical trial. The
Argus II retinal prosthesis system was recently awarded CE approval for
commercial use in Europe. While retinal prosthesis users have achieved
remarkable visual improvement to the point of reading letters and short
sentences, the reading process is still fairly cumbersome. This study
investigates the possibility of using an epiretinal prosthesis to stimulate
visual braille as a sensory substitution for reading written letters and words.
The Argus II retinal prosthesis system, used in this study, includes a 10 × 6
electrode array implanted epiretinally, a tiny video camera mounted on a pair
of glasses, and a wearable computer that processes the video and determines the
stimulation current of each electrode in real time.