What causes me to see rubbish! (2,3)
I believe the answer is:
my eye
'rubbish' is the definition.
(I've seen this before)
'what causes me to see' is the wordplay.
I cannot quite understand how this works, but
'see' could be 'eye' (I've seen this before) and 'eye' is found in the answer.
The remaining letters 'my' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for my eye that I've seen before include "bunk?" , "Certainly not" , "What rubbish!" , "I can see with this" , "Nonsense! (slang)" .)