Something like this is quite dangerous outside the question of sight I think. Someone with these implants will now have eyes that simply don't look right to others. Many people might either consciously or unconsciously look at these people as somewhat other than human, as some type of machine in some ways. The eyes are likely the most important physical feature a person has toward developing a sense of social communication. Perhaps implant recipients will end up wearing sunglasses at most times like the blind.
Those telescopic eyes look kind of awesome. But it does sound like the technology still has a long way to go. Only two thirds of people saw "notable" improvement. Meaning one third saw no improvement (or possibly even deterioration) after months of rehabilitation, and among those who saw improvement I imagine a lot of it would fall under the category of minor. Which seems like a pretty big risk considering that the operation does not look reversible. But then again, if you can't see already...
I think the whole point of the qualifier "notable" is to indicate that it would not be categorized as "minor."