> If I don't see your eyes

I think you really mean if you don't make eye contact.

Eye contact is a two-person activity. How does an autonomous car make eye contact with a person?

Something like this could be developed. For instance, the car could have an array of lights on its grill (think Knight Rider) that track in the direction of detected obstacles, if you don't see a light facing towards you then you know you are not detected and to use caution. Alternately a light on the front of the car could turn from yellow to blue to indicate its intent to yield.

A small screen (or more) might be a better option. It seems Mercedes made a concept version of the Smart with one, and the cars launched by Drive.ai already have them.