Interested that so few costume designers make helmets with good visibility - both for the actor, the character and the audience. Is it because in the real world, helmets have a face plate and the rest is opaque and so they think audiences wouldn't buy it? I just think from a real world point of view, visibility would be enhanced if more of the helmet was transparent - ie for the characters. The audience would be able to see the actors better, too. Just a thought.
On a similar note, there is a conceite with almost all space suits shown in sci-fi that bugs me. In almost every depiction the interior of the helmet has a bright light mounted to show the actor's face. In reality this would make it very difficult to see outside the suit due to the glare of the light on the inside of the faceplate.
like trying to see out the window of a well lit room at night.
If they did it the right way then you couldn't see the actor's face, know who they are, or see the expressions on their faces. You would be losing a lot to gain a little realism.