Or they take a dim view of it,
or frown on it
I was trying to think if you might have seen something like 'cast a cold eye on it,' but that's not really a fixed idiom, it's actually a quotation from Yeats:
Under bare Ben Bulben's head
in Drumcliff churchyard Yeats is laid.
An ancestor was rector there
long years ago, a church stands near,
by the road an ancient cross.
No marble, no conventional phrase;
on limestone quarried near the spot
by his command these words are cut:Cast a cold eye
on life, on death.
Horseman, pass by!http://rpo.library.utoronto.ca/poems/under-be...
I really can't think of anything else meaning 'disapprove.' If you're just looking for idioms with 'eye(s),' though, we could help brainstorm for that.