My best, shortest answer is that wallets should be compatible with talkback.

If they can scan a qr code a clerk guides them to, there should be a way for talkback to read the amount of the request. Perhaps there could be a place for braille next to permanent qr codes that shows for bitcoin lightning invoice, but most pos are digital and wouldn’t support that.

PS I am not completely blind, I have low vision and trusting a peer or counterparty isn’t something a person with vision problems wants to do.