in a wink

In a wink is an idiom often used to describe something that has happened or is going to happen in a very short time, or very quickly. Since a wink happens so quickly you usually dont even notice it, or when you are winking you hardly notice anything is different during that millisecond, in a wink can be used to describe just how quickly something will happen. Of course this isnt literal as virtually nothing happens that quickly, but a way to show it will happen quickly.