1 Visual Prosthesis 2 Microelectronic implants that provide identification of simple objects and motion 3 detection for blind patients have been tested and evaluated; further development is 4 needed for face recognition and reading implants.

Electronic visual prostheses have demonstrated the ability to restore a rudimentary sense of vision to blind individuals. This review paper will highlight past and recent progress in this field as well as some technical challenges to further advancement. Retinal implants have now been tested in humans by four independent groups. Optic nerve and cortical implants have been also been evaluated in humans. The first implants have achieved remarkable results, including detection of motion and distinguishing objects from a set. To improve on these results, a number of research groups have performed simulations that predict up to 1000 individual pixels may be needed to restore significant functions such as face recognition and reading. In order to achieve a device that can stimulate the visual system in this many locations, issues of power con- sumption and electronic packaging must be resolved.

[1]  M.S. Humayun,et al.  A biomimetic retinal stimulating array , 2005, IEEE Engineering in Medicine and Biology Magazine.

[2]  G. Brindley,et al.  The sensations produced by electrical stimulation of the visual cortex , 1968, The Journal of physiology.

[3]  Samip P. Shah,et al.  Electrical properties of retinal–electrode interface , 2007, Journal of neural engineering.

[4]  Daniel Palanker,et al.  Design of a high-resolution optoelectronic retinal prosthesis , 2005, Journal of neural engineering.

[5]  J. Hd..  Americans with Disabilities 1991-1992 , 1994 .

[6]  J. Weiland,et al.  Perceptual thresholds and electrode impedance in three retinal prosthesis subjects , 2005, IEEE Transactions on Neural Systems and Rehabilitation Engineering.

[7]  S. B. Brummer,et al.  Electrochemical Considerations for Safe Electrical Stimulation of the Nervous System with Platinum Electrodes , 1977, IEEE Transactions on Biomedical Engineering.

[8]  Manjunatha Mahadevappa,et al.  Assessment of Retinal Nerve Fiber Layer Thickness by Use of Optical Coherence Tomography and Retinal Dichroïsm Measurement: Preliminary Study , 2003 .

[9]  Takashi Fujikado,et al.  Electrophysiological studies of the feasibility of suprachoroidal-transretinal stimulation for artificial vision in normal and RCS rats. , 2004, Investigative ophthalmology & visual science.

[10]  Marco Zarbin,et al.  Current Treatment of Age-Related Macular Degeneration , 2007, Optometry and vision science : official publication of the American Academy of Optometry.

[11]  Gislin Dagnelie,et al.  Visually guided performance of simple tasks using simulated prosthetic vision. , 2003, Artificial organs.

[12]  C. Kufta,et al.  Feasibility of a visual prosthesis for the blind based on intracortical microstimulation of the visual cortex. , 1996, Brain : a journal of neurology.

[13]  Benita J. O’Colmain,et al.  Prevalence of age-related macular degeneration in the United States. , 2004, Archives of ophthalmology.

[14]  Avi Caspi,et al.  Spatial Vision in Blind Subjects Implanted With the Second Sight Retinal Prosthesis , 2007 .

[15]  R. Hornig,et al.  Chronic Epiretinal Chip Implant in Blind Patients With Retinitis Pigmentosa: Long-Term Clinical Results , 2007 .

[16]  Gislin Dagnelie,et al.  Real and virtual mobility performance in simulated prosthetic vision , 2007, Journal of neural engineering.

[17]  A. Y. Chow,et al.  The artificial silicon retina microchip for the treatment of vision loss from retinitis pigmentosa. , 2004, Archives of ophthalmology.

[18]  K. Wise,et al.  Silicon ribbon cables for chronically implantable microelectrode arrays , 1994, IEEE Transactions on Biomedical Engineering.

[19]  W. H. Dobelle.  Artificial vision for the blind by connecting a television camera to the visual cortex. , 2000, ASAIO journal.

[20]  J. Weiland,et al.  Pattern electrical stimulation of the human retina , 1999, Vision Research.

[21]  Benoît Gérard,et al.  Pattern recognition with the optic nerve visual prosthesis. , 2003, Artificial organs.

[22]  Stuart F. Cogan,et al.  Experimental Results of Intracortical Electrode Stimulation in Macaque V1 , 2003 .

[23]  J. Weiland,et al.  Visual performance using a retinal prosthesis in three subjects with retinitis pigmentosa. , 2007, American journal of ophthalmology.

[24]  James Weiland,et al.  In vitro and in vivo evaluation of ultrananocrystalline diamond for coating of implantable retinal microchips. , 2006, Journal of biomedical materials research. Part B, Applied biomaterials.

[25]  E. Zrenner,et al.  Compound subretinal prostheses with extra-ocular parts designed for human trials: successful long-term implantation in pigs , 2007, Graefe's Archive for Clinical and Experimental Ophthalmology.

[26]  神田 寛行.  Electrophysiological studies of the feasibility of suprachoroidal-transretinal stimulation for artificial vision in normal and RCS rats , 2005 .

[27]  R. Sharma,et al.  Management of hereditary retinal degenerations: present status and future directions. , 1999, Survey of ophthalmology.

[28]  Gislin Dagnelie,et al.  Facial recognition using simulated prosthetic pixelized vision. , 2003, Investigative ophthalmology & visual science.

[29]  R Clay Reid,et al.  Demonstration of artificial visual percepts generated through thalamic microstimulation , 2007, Proceedings of the National Academy of Sciences.

[30]  J Caprioli,et al.  The treatment of normal-tension glaucoma. , 1998, American journal of ophthalmology.

[31]  R.V. Shannon,et al.  A model of safe levels for electrical stimulation , 1992, IEEE Transactions on Biomedical Engineering.