What's up with the blue ocular?

[Markus Ramikin]

I'm doing my first playthrough, I just joined the Guardians on Taranis, and after the swearing in ceremony I'm wearing some kind of a blue eye piece that looks a bit like the Ocular from Risen 1. Except it's blue.

What gives? None of the other Guardians seem to be wearing something like this. Where did it come from? Did I miss some piece of story or dialogue that explains it?

[Nikolai81]

There's a mage who's often standing in the back left corner of the entrance hall, whom you can speak with regarding oculars regardless of whether you're a member of the Guardian faction or not. He'll give you a bit of information on it. It's probably made from the blue magical crystals, which explains the color. I think it's a big oversight that you're the only person wearing one, though.

[Markus Ramikin]

Right. I figured it might be for inserting those astral vision prisms, but the fact that nobody else wears one even though you know others use prisms too (there's a quest for it) threw me off. As did remembering Mendoza's ocular.