Green’s Dictionary of Slang

fully aware of a situation in all its ramifications, both obvious and hidden.

1977		D. Powis Signs of Crime 198: Ready-eyed Knowing the full story, awareness of the real ‘low-down’ of the situation.
2004		N. ‘Razor’ Smith A Few Kind Words and a Loaded Gun 2: We were top of the Flying Squad’s ‘most wanted’ list, and they loved nothing more than a ‘ready-eye’ ambush.