Skip to main content
. Author manuscript; available in PMC: 2012 Apr 16.
Published in final edited form as: Prog Brain Res. 2011;192:3–15. doi: 10.1016/B978-0-444-53355-5.00001-4

Figure 1.

Figure 1

Summary diagram illustrating various neuroprosthesis approaches to restore vision. Theoretically, any point along the visual pathway can be electrically stimulated to generate the perception of phosphenes and thus represents a potential site to implant a visual prosthesis. At the level of the retina, an implanted device generates electrical current to stimulate cells of the inner retina (i.e. ganglion and bipolar cells). Two approaches are possible: i) epi-retinal; in which the device is attached to the inner surface of the retina, and ii) sub-retinal; in which the device is placed within the underside of the retina. The optic nerve can be stimulated by implanting a cuff electrode around the nerve. In the cortical approach, electrodes are placed either intra-cortically or on the cortical surface in order to stimulate the visual cortex directly and thus bypassing afferent visual structures.