often seen in the street without a hat

If it wasn't for all the bafflingly unflattering beiges and heathers they insist on wearing themselves, I would be willing to bet good money that neither of those two women need glasses for anything more than, say, driving. They think 'oh, it'll be a bit more blurred at a distance, so what' rather than 'These people will be about as able to function as if someone had suddenly made them wear headphones playing loud thumping music and wouldn't let them take them off'.

Alternatively, they do it on purpose to make their protégées less confident and bolshy. I wouldn't put it past them.