For as long as people have been going blind desperate hopes have been held out for a cure. The electronic retinal chip under development would be an inferior solution compared to the regeneration of living cells. There is great research into gene therapy and photoreceptor transplantation. As with all areas of medicine and genetics, the vocabulary of stem cells is extensive. This brief summary of what stem cells are and the research into them is intended only as an introduction.
Many web pages are available for additional articulation.
There are ethical issues involved in using embryonic stem cells and such research is limited to private funding. So called signalling molecules and growth factors are necessary to the process. In mammals there is an inhibitory factor present which obstructs neural regeneration, a problem not present in amphibians. The reasons for the difference are being aggressively studied in labs of many nations, Canada, Israel, England, Japan, U.S. and all over Europe. The main difference seems to be the differences in the mammalian and amphibian immune systems.