We recently did a new pair of glasses for a lovely lady who unfortunately had a stroke and relies very much on her glasses to read the paper, do crosswords and the like. She was struggling with her old glasses (from another opticians) as the reading area on her bifocals was quite small. We gave her much larger round segment bifocals and upgraded her distance as well (especially so she can see the TV better). She wasn't even wearing her old glasses when she came in. We put the new ones on and immediately her face lit up! She smiled as she looked around the room - and continued smiling as we tried the reading chart. She could read a much smaller typeface than before and found reading much easier. She was delighted and - significantly - insisted on wearing them straight away.
Incidents like this really help us feel we're helping people out.