It's literally just the characters eyes that are animated. So yes, in first person, nothing changes and you won't notice your own character doing it. Though, what I will say is that while it may seem to some like "wasted effort" for a first person game, I'd put money on that it is a feature built into whatever 3D character model system they are using (unless I'm wrong and they built all this from the ground up). Even if they did built it custom, for those that play multiplayer, it certainly adds to the detail and I'm not one to complain about added detail and realism.