Elderly with stick/frame
Elderly without stick but frail/doddery
Temporary conditions which mean you cannot qualify for a blue badge:
Pregnant with SPD
Heavily pregnant so need extra room
Knee/hip replacement
Broken ankle/leg
Having or just had chemo/radiotherapy
Councils vary on what extent of poor eyesight, hearing, neurological disorders qualify for a blue badge:
Poor eyesight
Older children/adults with SN
Deaf people
Poor hearing
I personally think all of them, as long as they don't nip in a space that you are waiting for, cos that's just rude :)