Well, the eyes are also features as an on looker. A person looking into the lifes or another civilisation. This eye in BR is like Tyrell looking over the poor Earth in his big building. This eye in BR is like the replicants trying to look to the humans (tyrell mainly) for more life and be treated as human. The eye in BR is like Decard looking for something he's missing in his life. Memories that was before but he isn't sure if they are real or not. The eye in BR is like our eye, watching the 'Hades' scene, with the whole flames and panning of the city scapes. The eye in BR is like what everyone sees around them. The messes, the advertising, the crowded streets. This eye in BR is the "LOOKING" of your view, or Deckard's view, or the replicants' views and of Tyrell's views and so on and so forth. Ha.
And yes, the whole window to the soul thing is a definite worth mention.