For example, the glasses could automatically magnify small text that you are reading. They could speak out directions as you walk around a city. They could help you identify products at the store.
That's just a handful of things I came up with off the top of my head. Consider all of the assistive devices (mostly expensive btw) that are currently being used by the blind (and don't forget the deaf!), and think of how these glasses could augment or even replace what's available now. It could be huge.
I'm specifically asking if they are going to go the extra mile and make this technology blind-accessible. The iPhone is extremely successful product for the blind for example because it has a well thought out alternate input mode that they spent a lot of time and effort developing.
If Google isn't going to actually add accessibility provisions in then this seems like rolling up to a environmental charity event in a custom Hummer.
Imagine these glasses being able to tell you what colour that shirt is; no more garish colour clashes for people with colour blindness. Or a bajillion other ideas.
If the information is there, some kind of speech assist plugin could be a literal lifesaver for the blind.
Everyone I've ever met who works for a charity is massively pragmatic about these things. They would understand that he's not doing it to mock the blind and accepting that would very quickly move on to the potential good for the charity.
Anyway, if you're bind, your lenses will be opaque and you'll be using audio, and maybe ... just Google Jordy on Star. This type of device will change your life if you're blind. You could "read" HN, for example.