@oelli: as far as I can see from the picture he used a meshsmooth modifier. There are tutorials on the internet that can learn you understand and use the meshsmooth correctly. For this hard edge modeling look at this pic
this way you can have smooth rounded surfaces but hard edges, just what you need.
it's in a tutorial for modeling the helmet of iron man
Model the Ironman Helmet - CGArena
or this one, movie goes fast but just take a good look at what he does and what for.
Hard Surface Modeling: The Making of Binocular Cover