Are there any UIs or hard wallets that work well for a BTC user who is blind or visually impaired?
I don't know of any wallet specifically developed with blind users in mind, but I think there is a solution nonetheless: using the daemon (bitcoind) that is a part of bitcoin-core, through a CLI text-to-speech program. Being a command line tool, the daemon is entirely text-based, so it should be usable in this way.
You can use the daemon to synchronize with the bitcoin network, create receiving addresses, and craft outgoing transactions. It is a very full-featured wallet, despite having a clunkier user experience than some other options.
I am not extremely familiar with the options available for text-to-speech accessibility programs, but bear in mind that there are likely some security considerations when choosing which accessibility program you will be using. Ideally, you would use bitcoin-core and this accessibility program on an offline computer (ie, one that never, ever connects to the internet), to ensure that there are no potential data leaks (does the accessibility program communicate on-screen data with a cloud server? etc).
The good news is that if used correctly, you won't have to sacrifice privacy, security, or sovereignty in using this sort of solution, but the bad news is that the solution isn't easy to use. To quote the user Steve Ellis in the question linked in Murch's comment above:
The short of it is Bitcoin already has a subpar reputation for user experience, and it doesn't get better as you dig into accessibility