Human beings are the only primates that show the whites of their eyes. This gives us a unique range of possible signals that we can communicate with just our eyes. By knowing what different eye signals mean, and how to make those signals, we can more effectively get others to trust us and like us instantaneously.
Contracted Pupils versus Dilated Pupils
You may have noticed that your pupils contract (get smaller) or dilate (get larger) when your mood changes. When you get excited about something, your pupils can actually dilate up to four times their original size – that’s pretty drastic!
Conversely, an angry or negative mood can cause your pupils to contract a lot. You probably have angry coworkers or friends who complain to you: next time they do, notice how their pupils become “beady” or like “snake eyes.”
Say you want to dilate your pupils on purpose to convey your interest or excitement in what someone else is talking about. How can you do this intentionally? Thankfully there’s an easy trick: Un-focus your eyes, blurring your vision as much as you can. You’ll know you’re doing this correctly if your eyes feel very relaxed.
Make the “eyebrow flash”
The “eyebrow flash” is an unconscious eyebrow raise that lasts about 1/5 of a second: it’s a subtle but effective gesture that signals a long-distance “hello!” Normally, you don’t raise your eyebrows to greet a random stranger you pass on the street. But if you do want to get to know a stranger, try this friendly and simple gesture! You’ll likely find that they’ll return the eyebrow flash and smile; some will even come over to strike up a conversation.
Keep your eyes open and avoid frowning
It’s easy to allow our resting eyes to half-close and our faces to droop into a frown, especially when we’re preoccupied with something. But recent studies have found  that these habits make us appear as though we’re tired and in a bad mood. People associate exhaustion with poor cognitive performance. So it probably shouldn’t come as a surprise that if you don’t look alert, people will unconsciously assume that you’re less intelligent.
Long story short: Keep your eyes looking bright and that face smiling!
Use low OR high eyebrows to signal authority or submission
Low-set eyebrows signal authority. John F. Kennedy had what are known as “medially down-turned” eyebrows, which gave his face a permanently authoritative (and concerned) look that appealed to voters.
If you don’t already have low-set eyebrows, but you want to project authority, you can make your eyebrows thicker. This will shorten the distance between your eyes and the eyebrows and thereby create the illusion you have low set eyebrows.
By contrast, you can take advantage of high or arched eyebrows to signal submission or sexiness. Scarlett Johansson’s eyebrows, while thick, are high and arched. If you don’t already have high eyebrows and want to signal sexiness, consider getting them sculpted or shaped to achieve this look.
Narrow your eyelids and focus your gaze to establish authority
Many of us need to project our authority from time to time, whether it’s as a manager speaking to employees or a teacher speaking to a large class. If you have naturally soft eyes, but want to project authority, practice the “Power Stare.”
Try not to blink excessively while you maintain eye contact. Narrow your eyelids and focus closely on the other person. By doing this, you are demonstrating that you are utterly unintimidated, and that you are establishing your dominance.
In fact, this is exactly what predatory animals do just before they strike their prey. While you probably plan to use this gaze in the workplace or in much calmer social scenarios, the effect can be useful from time to time.
To signal submissiveness, lower the head and look up
Just as it can be useful to establish power and dominance, it’s equally important to know how to signal submission. Animals do this too in different ways: dogs sometimes expose their bellies to show that they are not trying to pose a threat to other, larger dogs. Projecting submissiveness is a method of gaining another person’s trust.
If you want to try it out, lower your head just slightly and look up. This makes your eyes appear larger and more “innocent” or “childlike.” It’s easier to do this if you’re shorter than the other person, but if you’re the taller one, you can also try it out while you’re seated. Just make sure not to overdo this one – it can look less than subtle!
Don’t blink too frequently or too slowly
Both over-blinking and under-blinking can be warning signs to others. People under pressure will often dramatically increase their blinking rate, while people who blink very slowly are unconsciously signaling that they are bored or feel superior to you. Strangers and friends alike will pick up on these signals. If you want to gain someone’s trust and respect, blink at a regular rate to show that you trust and respect them too.
To establish strong, peer-to-peer rapport, hold eye contact about 60-70% of the time
More than this can be unsettling, while less than appear overly meek. 60-70% is the sweet spot for an extended gaze that creates intimate feelings. This will encourage people to like and trust you.
This is why you might find it hard to trust a nervous person who meets your gaze less than a third of the time. Think about this for yourself: you might be the kind of person who avoid eye contact, but make the attempt to hold enough to gain another person’s trust.
Consider avoiding dark-tinted glasses as well, especially when you’re trying to establish a strong relationship with another person – either business or personal. The sunglasses will make others feel you are either staring at them or trying to avoid them.