PMID-18429703 Psychophysical evaluation for visual prosthesis.
- Visual prostheses are clinical and preclinical trials!
- cochlear implants function with 16-20 electrodes; retina is 120e6 photoreceptors and 1.2 optic nerve fibers.
- Argus 2 retinal implant has 60 electrodes. visual information impoverished.
- In the heyday of prewar German scientific discovery, Foerster (3) established that electrical stimulation of the visual cortex in an awake patient during a neurosurgical intervention produced the percept of dots of light, called phosphenes, and that the location of a phosphene changed with that of the electrical stimulus.
- people originally thought that loss of the photoreceptors would lead to degradation of the RGCs; this appears not to be true.
- There is broad consensus that functional vision restoration is predicated on prior visual experience; this is different than cochlera prostheses, which work on congenitally deaf people.
- Visual development depends on nearly a decade of high-resolution perception, and cannot be emulated later in life through a low-bw prosthesis.
- There are at the present time at least 20 distinct research groups in at least 8 countries actively engaged in visual prosthesis development.
- discuss a lot of pre-clinical testing & all the nitty-grity details, e.g. how to make a low res prosthesis work for reading.
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