02-09-2017, 01:00 PM
A visual prosthesis often called a bionic eye, is an experimental visual device intended to restore functional vision in those who suffer from partial or total blindness. Many devices have been developed, usually modeled in the cochlear implant or bionic ear devices, a type of neural prosthesis in use since the mid-1980s. The idea of using electric current (for example, electrically stimulating the retina or visual cortex) to provide sight goes back to the eighteenth century, discussed by Benjamin Franklin, Tiberius Cavallo and Charles LeRoy.
The ability to give sight to a blind person through a bionic eye depends on the circumstances surrounding the loss of sight. For retinal prostheses, which are the most frequent visual prosthesis in development (due to the ease of access to the retina among other considerations), patients with vision loss due to degeneration of photoreceptors (retinitis pigmentosa, choroemia, degeneration geographic atrophy macular) are the best candidates for treatment. Candidates for visual prosthesis implants find the procedure more successful if the optic nerve developed before the onset of blindness. People born with blindness may lack a fully developed optic nerve, which normally develops before birth, although neuroplasticity makes it possible for nerve and vision to develop after implantation.
Visual prostheses are being developed as a potentially valuable aid for people with visual impairment. Argus II, co-developed at the University of Southern California Eye Institute (USC) and manufactured by Second Sight Medical Products Inc., is now the only device of its kind that has received marketing approval (CE Mark in Europe in 2011). Most other efforts remain investigative; Retina Implant AG's Alpha IMS was CE marked in July 2013 and is a significant improvement in resolution. It is not, however, approved by the FDA in the United States.
The ability to give sight to a blind person through a bionic eye depends on the circumstances surrounding the loss of sight. For retinal prostheses, which are the most frequent visual prosthesis in development (due to the ease of access to the retina among other considerations), patients with vision loss due to degeneration of photoreceptors (retinitis pigmentosa, choroemia, degeneration geographic atrophy macular) are the best candidates for treatment. Candidates for visual prosthesis implants find the procedure more successful if the optic nerve developed before the onset of blindness. People born with blindness may lack a fully developed optic nerve, which normally develops before birth, although neuroplasticity makes it possible for nerve and vision to develop after implantation.
Visual prostheses are being developed as a potentially valuable aid for people with visual impairment. Argus II, co-developed at the University of Southern California Eye Institute (USC) and manufactured by Second Sight Medical Products Inc., is now the only device of its kind that has received marketing approval (CE Mark in Europe in 2011). Most other efforts remain investigative; Retina Implant AG's Alpha IMS was CE marked in July 2013 and is a significant improvement in resolution. It is not, however, approved by the FDA in the United States.