Eyebrows show feelings
Eyebrow mirror the what eyes are trying to feel, the eyebrows are what makes the eyes crinkle up in a smile since the cheeks are being pushed up the eyebrows push down. It makes a pleasing shape that the other person can just looks and knows what they are feeling. Have you noticed a "fake" smile before? the eyebrows are nearly neutral, they often say that "his eyes don't crinkle at the corner". People that shave their eyebrows off or have botox injections to this part, people find that they seem "expressionless".
Eyes show thought
Eyes mimic what the person is thinking, not so much the feeling. Why should they? they have the eyebrows to do that job.
Eyes can tell you a lot about what the person is trying to talk about (the cogitative thought pattern for most people is this "he's talking about that", they have to dive through their memories to find a conclusive match to what the person is talking about and then say "ah, yes I had a trip to Canada once" even if the person is talking about their recent trip to India, the most relevant memory that the person can dredge up is going to Canada) So you will see their eyes dive around in their memory, it might be a simple "flick" and then back to the talker again if the memory is not that long ago, a week or so. Would be longer if the memory is quite awhile ago, the person might remember going to Canada but trying to remember what they did there .
It can also be the deciding factor when you first meet someone if they seem to not maintain eye contact and their eyes are roving you might say "I didn't really like that person, his eyes are shifty".
Though usually is just because he might be shy and remembered that he left his lecture notes at home, panicking about it and thinking that "did he feed the cat before he came here?"
They say that it is more likely that the person that is trying to keep more direct eye contact with you even if they are finding it more uncomfortable is the liar, with the appropriate body language of course.
Eyes are important in role of sight, but out of the two pupils in the picture do you find more attractive?
Good for you, you chose the larger pupil... It's a trick question, you know why? We are designed to find larger pupils more attractive because of the one thing.
It shows attraction, if the person is in shock or disgust the pupil shrinks to a pinpoint and if the person loves something that or is showing interest/attraction in someone the pupils dilate to might even be nearly to the outer edge of the eye.
You can see if someone remembers and recognises you from this, their eyes will get bigger.