I posted not so long ago on the topic of foundational work in artificial sight:
The present mainstream approach involves building a grid of electrodes in place of the retinal cells lost to forms of degenerative blindness; images captured by a worn camera are analyzed and the electrodes stimulated appropriately. ... Progress in this model is at present a matter of making implantation safer and more reliable, greatly increasing the density of electrodes, and improving the ability to translate a camera's view into a helpful picture - a combination of medicine, electrical engineering, and computer vision research. The end result of this form of technology will never produce anything more than a detailed, glowing sketch of dots and lines for the patient: it is not true vision as experienced by those of us fortune enough to retain our sight. Nonetheless it works - already providing a great improvement for patients over being blind - and it will serve as a foundation for later forms of artificial sight technology.
researchers based in Germany have developed a retinal implant that has allowed three blind people to see shapes and objects within days of the implant being installed. ... The device - known as a subretinal implant - sits underneath the retina, directly replacing light receptors lost in retinal degeneration. As such, it uses the eyes' natural image processing capabilities beyond the light detection stage to produce a visual perception in the patient that is stable and follows their eye movements. Other types of retinal implants - known as epiretinal implants - sit outside the retina and because they bypass the intact light-sensitive structures in the eyes they require the user to wear an external camera and processor unit.
"The present study...presents proof-of-concept that such devices can restore useful vision in blind human subjects, even though the ultimate goal of broad clinical application will take time to develop."
This seems like a natural evolution if it can be made to work in a practical fashion - cut out the aspects of the system that were awkward to manage in favor of an implant that can stand alone. The obvious path for incremental improvement is still to increase the number and density of electrodes, and thus the resolution of the glowing grids and images seen by the patient. Work on that area will likely benefit numerous similar lines of development in the artificial sight community.
There remains a big difference between "vision" and "useful vision" - but I imagine that the gap will close as this technology evolves further. An implant that replaces one part of an eye is an invitation to build a second implant that attaches to it and replaces a neighboring feature...and so forth. This research and development community will give the tissue engineers a run for their money.