Seedily manipulated protection for viewers (7)
I believe the answer is:
eyelids
'protection for viewers' is the definition.
(eyelids protect eyes or 'viewers')
'seedily manipulated' is the wordplay.
'manipulated' is an anagram indicator.
'seedily' anagrammed gives 'EYELIDS'.
(Other definitions for eyelids that I've seen before include "They drop in sleep" , "covers for lamps" , "covers for lights?" .)