Feel something of a blow to experience second sight thus? (3,6)
I believe the answer is:
see double
'a blow to experience second sight thus?' is the definition.
I can't judge whether this definition defines the answer.
'feel something' is the wordplay.
'feel' becomes 'see' (seeing is a kind of feeling).
'something' becomes 'double' (I can't explain this - if you can you should give a lot more credence to this answer).
'see'+'double'='SEE DOUBLE'
'of' is the link.
Can you help me to learn more?
(Other definitions for see double that I've seen before include "Drunks might well" , "experience an illusion" , "Observe two of everything" .)