A real eyesore (4)
I believe the answer is:
stye
'a real eyesore' is the definition.
'stye' can be an answer for 'eyesore' (I've seen this before). I'm not sure about the 'a real' bit.
'a real eyesore' is the wordplay.
I cannot really see how this works, but
'real' could be 'e' (e is a kind of real) and 'e' is present in the answer.
'eyesore' could be 'sty' (I've seen this in another clue) and 'sty' is found within the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for stye that I've seen before include "Inflammation around the eye" , "It pains viewer" , "Climb" , "Eyelid infection" , "Eyelid sore" .)