This is one of the lie along with "brain cannot grow new neurons".
It is only because you believe in it that you lose vision acuity and your brain get rotten.
Old people can see very well. Old people can grow new neurons and maintain their mental capacity.
If you use science to justify your point of view, at least get updated.
Physics isn't like religion - it doesn't give a sh*t about belief.
People know physics, religious nuts believe their religion (and erroneously mistake that for knowledge, despite the 100.0% perfect contradiction of terms).
Small detail, insanely massive difference. But pointless trying to explain belief vs. knowledge to a believing person (IMHO it's like their brains mashed those two completely different items into one, I have no better explanation for that permanent mistake those people make over and over and over again).
I won't even go into the percentage of (religious or non-religious) eldery who live with severely degraded vision.
Neuronal cells can recover, but only to some extend and with drastically reduced success with increased age.
No thanks to religion, scientists were able to assist and amplify the process to a high degree - but even that has limits.
Anyway superresistant (to education), tell your BS story to some paraplegic or nearly blind, elderly person.
If ever you get chocked or hit with a cane on your head by a pissed-off eldery or someone stuck to a wheelchair - it's well-deserved.
Seriously, the amount of religious BS and nonsense around threads like this is mind-bending. Never seen so much stupidity and human mad cow disease in an internet forum before, in such a concentrated form. Religious nuts truly are mental zombies. Frightening to know such people freely roam the planet and may even look healthy to the outside.
People believe in physics, so it exists. Your reality is formulated by beliefs. If you truly believe in something impossible, it can happen. Hence, nothing is impossible.