Not seeing straight when angry, I'd say (5-4)

I believe the answer is:

'not seeing straight' is the definition.
(having eyes looking in different directions)

'angry i'd say' is the wordplay.
'angry' becomes 'cross' (I've seen this before).
'say' shows a homophone (sound like).
'id' sounds like 'eyed'.
'cross'+'eyed'='CROSS-EYED'

'when' is the link.

(Other definitions for cross-eyed that I've seen before include "Squinting", "With a squint".)

I've seen this clue in The Guardian.