Experiments and studies have shown that this might be due to the fact that the visual cortex will take over a similar role in blind people as it does for people with intact eye sight. The brain uses different sensory inputs in that case and the visual brain structure is not restored after eye sight recovery.
This is still an ongoing field of research of course, but so far congenital blindless seems to be incurable, regardless of whether the sensory apparatus could be restored or replaced. Note that this only means seeing like a non-blind person. Some limited visual perception is still possible, just not "normal" sight.
1. https://news.mit.edu/2011/vision-problem-0411
2. Shape recognition
3. Face recognition
https://www.newyorker.com/magazine/1993/05/10/to-see-and-not...
> It was, rather, the behavior of one mentally blind, or agnosic—able to see but not to decipher what he was seeing.
And while he does get better, it does end up with:
> But then, paradoxically, a release was given, in the form of a second and now final blindness—a blindness he received as a gift.
Cf: https://web.archive.org/web/20240111185639/https://www.newyo... (older version does not trigger the paywall or at least can disable it while it's loading).