I happened to be working near the small Sainsbury's in Great Portland Street, W1, on Friday - what a lovely bunch they are.
One young chap cheerfully went out to the back to check if they had something in stock; he was a few minutes and as I was standing there waiting another asked if I needed help. then when I was at the tills observed a young woman helping an older blind customer. I think she'd done his shopping for him and loaded his stuff into his backpack and helped him on with it, with another colleague sorted his payment, handed him another bag with shopping and led him out the door.
The blind customer was dealt with professionally, kindly and with such good heart, even telling him the use by date on the milk. There are lots of good people everywhere. I'm not on Twitter so can't give this a wider audience.