I do observe body parts and body language in all people I meet. This gives valuable information and a more correct interpretation of the person, compared to words they say.
That said, being stared at can feel very uncomfortable, depending who it is and how it is done, of course :)
That said, I never had big problems with men staring at my chest. Probably because my brain is bigger than my breasts, so they look me in the eyes instead, lol