specific visual tasks. Simulation results indicate that 600-1000 electrodes would be required to enable subjects to perform a wide variety of tasks, including reading, face recognition, and navigating around rooms. Thus, the available spatial resolution of retinal implants needs to increase by a factor of 10, while remaining small enough to implant, to restore sufficient visual function for those tasks. It is worth to note high-density stimulation is not equal to high visual acuity (resolution), which requires a lot of factors in both hardware (electrodes and coatings) and software (stimulation strategies based on surgical results). Current status and future developments Clinical reports to date have demonstrated mixed success, with all patients report at least some sensation of light from the electrodes, and a smaller proportion gaining more detailed visual function, such as identifying patterns of light and dark areas. The clinical reports indicate that, even with low resolution, retinal implants are potentially useful in providing crude vision to individuals who otherwise would not have any visual sensation. However, clinical testing in implanted subjects is somewhat limited and the majority of spatial resolution simulation experiments have been conducted in normal controls. It remains unclear whether the low level vision provided by current retinal implants is sufficient to balance the risks associated with the surgical procedure, especially for subjects with intact peripheral vision. Several other aspects of retinal implants need to be addressed in future research, including the long term stability of the implants and the possibility of retinal neuron plasticity in response to prolonged stimulation. The Manchester Royal Infirmary and Prof Paulo E Stanga announced on July 22, 2015, the first successful implantation of Second Sight's Argus II in patients with severe Age Related Macular Degeneration. These results are very impressive as it appears that the patients integrate the residual vision and the artificial vision. It potentially opens the use of retinal implants to millions of patients with AMD. See also Retinal regeneration References External links Japan Retinal Implant Project - The Retinal Implant Project - rle.mit.edu National Eye Institute of the National Institutes of Heath (NIH) Biomedical engineering Neuroprosthetics Implants (medicine) Artificial organs Emerging technologies Blindness Eye Prosthetics Medical devices