Look at dazzling plant with small white and purple flowers (9)
I believe the answer is:
eyebright
'plant with small white and purple flowers' is the definition.
'look at dazzling' is the wordplay.
'look at' becomes 'eye' (I've seen this before).
'dazzling' becomes 'bright' (similar in meaning).
'eye'+'bright'='EYEBRIGHT'
(Other definitions for eyebright that I've seen before include "Simple" , "that could help the viewer" , "A plant; they're big (anag.)" , "Traditional remedy for vision problems" , "Wild flower - get by hire (anag)" .)