People often squint at you when they do not like you or something you are saying. It can indicate suspicion. (The same principle as eye-blocking above, blocking out what they do not like). If you see someone squint at you (and it is not low light) address them directly and clarify your point. They often will be amazed you picked up on their disbelief.
We raise our eyebrows in a quick flash to draw attention to the face and send clear communication signals. I have noticed I do this when I want to be understood or emphasize a point. Raising the eyebrows is a gesture of congeniality and an indication we want to get along and communicate better.
Mimicry or synchrony is when your behavior mimics or mirrors someone else’s. You can mimic someone else’s eye movement to build rapport. Although, use this with caution–it is difficult to mimic someone in a genuine, subtle way. If they notice, it can feel creepy or forced.
This usually denotes uncertainty or the need for more info. If someone is sideways glancing and also has a furrowed brow, it can indicate suspicion or critical feelings. A sideways glance with eyebrows up, on the other hand, usually indicates interest or is a sign of courtship.
If someone lifts their head and looks down their nose at you, it usually means they feel superior.
Darting eyes always mean the person feels insecure. They often are looking for escape routes from talking to you.
During presentations, you actually can use people’s eyes to lead them in topics. Use your pen to garner attention. You actually can hold it at eye-level and then lift the person’s head when you make a point. You also can compare points by drawing people’s eyes to the right and left.