In latin "oculus" means "eye", and, as you know, "eye" is the tool of extraction of the visual information, i.e. - an instrument, which we use to explore the image, the vision of the world around us.

EV is Exploration Vessel. Yeah. That's it.

And -ix ending just sounds cool and aesthetic for me, also moving the word from masculinum genus to neutrum, which is also kinda approptiate for a race of clones, just to mark their similarity one more time.