View affirmation cardinal welcomes (8)
I believe the answer is:
eyesight
'view' is the definition.
(I've seen this before)
'affirmation cardinal welcomes' is the wordplay.
'affirmation' becomes 'yes' (yes is a kind of affirmation).
'cardinal' becomes 'eight' (eight is a cardinal number).
'welcomes' indicates putting letters inside.
'yes' put within 'eight' is 'EYESIGHT'.
(Other definitions for eyesight that I've seen before include "Requirement to look" , "Ability to see" , "Visual faculty" , "Perceptive faculty" , "Yes, eight required for vision" .)