A naval commander of singular vision (6)
I believe the answer is:
nelson
'a naval commander' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for nelson that I've seen before include "English admiral, mortally wounded at Trafalgar" , "'England expects' admiral" , "grip" , "18th century admiral" , "Sea-lord who loved Lady Hamilton" .)