Nostalrius Begins - Quality wow vanilla realm (1.12)

I've googled this already and it says to create a macro /cast !Eagle Eye

But i've been trying this over and over and the macro spell is not lit up and it just doesn't work, i'm only allowed to eagle eye once. So how do people do it in vanilla?

Yup, server changes the spell while channeling, and the second cast will just break it. So using an any 2-nd click macro via action bar number or other primitive stuff will do nothing.
Even if solution exists, it isn't obvious. I think there's a way to do that using a complex /script macro, but mechanic of this spell is a little bit tricky.

I don't think you can do it on private servers. I remember doing this on retail, with Far Sight and Mind Vision, but it doesn't seem to work on any private server I've played.