Aren't I excited, being a bit of a looker? (6)
I believe the answer is:
retina
'a bit of a looker?' is the definition.
(part of an eye, something which looks)
'aren't i excited' is the wordplay.
'excited' is an anagram indicator.
'arent'+'i'='arenti'
'arenti' is an anagram of 'RETINA'.
'being' is the link.
(Other definitions for retina that I've seen before include "Part of the eyeball" , "Bad tear in part of the eye" , "Light-sensitive membrane in the eye" , "Back surface of eye" , "Ocular membrane" .)