Lack of foresight in my work leads to inadequate assessment (6)
I believe the answer is:
myopia
'lack of foresight' is the definition.
'my work leads to inadequate assessment' is the wordplay.
'work' becomes 'op' (abbreviation for opus**).
'leads to' suggests taking the first letters.
The first letters of 'inadequate assessment' is 'ia'.
'my'+'op'+'ia'='MYOPIA'
'in' acts as a link.
(Other definitions for myopia that I've seen before include "Seeing problem" , "Short-sightedness" , "Condition of short sightedness" , "lack of long-term vision" , "complaint" .)