Essentially they're missing the most difficult part: optic nerve regeneration. There have been competing advances [
$1][
$1] in this field, but scientists are still taking baby steps, and it takes an average of 12 years between the time a new drug is thought and the time it gets FDA approval. This miraculous drug is yet to be found, and 5 years have passed since the actual first ever restoration of vision in mice [
$1].