Sight, or what may adversely affect it (7)
I believe the answer is:
eyesore
'sight' is the definition.
(eyesore can mean a horrible sight)
'or what may adversely affect it' is the wordplay.
I cannot quite understand how this works, but
'or' is present in the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for eyesore that I've seen before include "Hideous sight" , "offensive to viewers" , "Ugly object, hard on the sight" , "Ugly structure" , "Ugly prospect" .)