Look at top batter? (6)
I believe the answer is:
eyelid
'batter?' is the definition.
(as in batting your eyelids)
'look at top' is the wordplay.
'look at' becomes 'eye' (I've seen this before).
'top' becomes 'lid' (lid is a kind of top).
'eye'+'lid'='EYELID'
(Other definitions for eyelid that I've seen before include "Ocular shutter" , "Natural optical cover" , "Where stye may occur" , "Skin over viewer" , "Covering for organ of sight" .)