Len, brisk, replacing screens attached to bridle (8)
I believe the answer is:
blinkers
'screens attached to bridle' is the definition.
I can't tell whether this defines the answer.
'len brisk replacing' is the wordplay.
'replacing' indicates an anagram (re-placing: placing the letters again).
'len'+'brisk'='lenbrisk'
'lenbrisk' with letters rearranged gives 'BLINKERS'.
Can you help me to learn more?
(Other definitions for blinkers that I've seen before include "Limiters of horse's vision" , "Horses' eyeshades?" , "They prevent a horse from seeing sideways" , "They prevent a horse from looking sideways" , "what might be placed on racehorse" .)