The significant therapeutic potential offered by neural recording

is evident in recent reports of multi-electrode prostheses implanted in the motor cortex of humans and non-human primates, enabling the dextrous operation of a robotic arm and hands (Collinger et al., 2013 and Hochberg et al., 2012). This dexterity will undoubtedly be greatly enhanced by the integration of sensory feedback (e.g. mechanosensation), which has already been demonstrated in macaques via microstimulation of somatosensory cortex (Berg et al., 2013, O’Doherty et al., http://www.selleckchem.com/products/BEZ235.html 2011 and Tabot et al., 2013). Beyond the experimental domain, electrical stimulation of the brain, spinal cord and peripheral nerves via implanted electrodes is in use clinically for the treatment of movement disorders (Williams and Okun, 2013), psychiatric disorders (Williams and Okun, 2013), chronic pain (Plow et al., 2012), epilepsy (Bergey, 2013), neurogenic bladder (Lay and Das, 2012) and for the restoration of lost sensory functions such as hearing (Carlson et al., 2012 and Shepherd et al., 2013). Currently, the most commercially successful sensory prosthesis is the cochlear implant for treatment of neural deafness, of which the US National Institutes of Health reports there were 324,200 recipients worldwide in December 2012 (National Institute on Deafness and Other Communication Disorders, 2013). Restoration of

visual perception to the blind or severely vision impaired is another area of intense research effort and two retinal bionic vision devices are now commercially available (Weiland and Humayun, 2014). We briefly review these PKC inhibitor and other devices being developed for the restoration of functional vision in blind individuals,

before focusing on cortical visual prostheses and the challenges facing developers of these devices. We describe an implant currently being developed by the Monash Vision Group which is currently in the preclinical testing phase. Recent meta-analyses examining next the global burden of blindness and vision impairment highlight the scale of these ongoing public health concerns. In two separate studies, the total number of people with vision impairment in 2010 was estimated at 191 million (Stevens et al., 2013) and 285 million (Pascolini and Mariotti, 2012) globally, with the number of those legally blind estimated at 32 and 39 million respectively. The most recent of these studies found the most common causes of blindness to be cataract (33%), uncorrected refractive error (21%) and macular degeneration (7%) across all regions studied (Stevens et al., 2013). As would be expected, there is significant regional variation in these figures; in high-income regions including Western Europe, Australasia (Australia and New Zealand), Asia-Pacific and North America, the most common causes are macular degeneration (16.1–19.5%), uncorrected refractive errors (14–14.1%) and cataract (12.7–14.