General sense of characters caught up in short-sightedness (4)
I believe the answer is:
gist
'general sense of characters caught' is the definition.
I can't tell whether this definition defines the answer.
'up in short-sightedness' is the wordplay.
'up' is a reversal indicator (in down clue: letters go upwards).
'in' indicates a hidden word.
'tsig' is hidden within 'short sightedness'.
'tsig' reversed gives 'GIST'.
Can you help me to learn more?
(Other definitions for gist that I've seen before include "The essential point of something" , "Meat" , "The pitch on the matter" , "General meaning or main point" , "Central idea" .)