Different mechanisms, you’re born with ~100x the amount of neurons you’ll have as an adult, those normally used for hearing get adapted and trained on other stimuli.

Make sure their glasses prescriptions are up to date & that they are engaged with the world (and not slipping away) too.

There is no pre-existing neutral training in a newborn's brain.

Adults who become deaf lose a stimulus that their brains are already trained to use.

I would assume they compensate with other senses and so if they get blind at high age they are at equal risk.