Tear in distress in one's eye (6)
I believe the answer is:
retina
'in one's eye' is the definition.
'tear in distress' is the wordplay.
'distress' indicates anagramming the letters.
'tear'+'in'='tearin'
'tearin' with letters rearranged gives 'RETINA'.
(Other definitions for retina that I've seen before include "Light-sensitive eye lining" , "What's behind the humour" , "Ocular membrane" , "Back surface of eye" , "Bad tear in part of the eye" .)