Although eyes are not open yet, they can be quite comical in expressions. A yawn here and there. Making noises as I move them from the milk slot they want. Even complaining as I put them in the scale. I think this is all interesting. Imagine if you couldn't see and all these things were occurring around you. You can't hear yet nor see so you rely on touch and your sense of smell.
It is important to slow condition them to things they are not familiar with. Little by little they go - oh I like that! It is important to always hold them before eyes are open and after. A stroke here and there - a snuggle - it is all good!