Can woman really see the difference when you stare at them?

I doubt detecting it it's a male/female difference. I think anyone who's observant enough has a chance at noticing. When we are attracted to someone our body gets flooded with various chemicals and responds physiologically - pupil dilation is one of the responses. So yeah, someone who's madly in love may have that big puppy dog look on their face :)

you can tell a lot from eyes the way they look and the way you smile plus your eyes/pupils actually dilate when you look at someone you care about

The eyes are a dead giveaway. But it is not sex specific. Women as well as men can tell this if they know how and where to look- and what to look for.

Course they do. You can tell a mile off plus body language. Dead giveaway

Not the eyes. You were drooling.

It shows sometimes.