Great question!

Eyes can express emotion. They will get watery with tears when sad or scared, they get wider with surprise, the corners turn up a tiny bit with a smile, the lids droop slightly expressing pleasure.

When someone says "you have that look in your eyes" it can mean many things- that you look like you have mischief in mind, that you are angry. The saying implies it is a look they are familiar with and could be a feeling you express often.

Feel free to ask them "what look?". The answer usually says more about them than you but sometimes they know you well enough to read that look in your eyes very accurately.

This is such a great question! It’s really more of the expression as a whole than anything specific with the eyes. People can have “micro expressions” which are tiny facial movements: a slight narrowing of the eyes, a small tightening of the corners of the mouth that would indicate annoyance, but not an outright scowl. If I were to look at someone I didn’t know with this micro expression, I wouldn’t really tell their emotions. If it were someone I knew well, those micro expressions would let me know they were annoyed, but I’d say to my husband, “I can tell you’re irritated by the look in your eye”

Everything everyone else has sad, also, people frequently demure from eye contact. It takes a lot of confidence to maintain eye contact with fully opened eyes. So
If someone is saying something, and have the conviction to maintain full unbroken eye contact it allows the viewer to project an intensity of whatever feeling, joy, sadness, irreverence, or whatever “spark” one sees.

So I am VI but have frontal vision and could see fairly well when I was younger. If I understand what you are asking, I think what you mean is when a person had an angry look in their eyes, or that someone gave them an incredulous look.

If that is correct, it means the way someone’s eyes look to another person. It is tied to how people show emotion on their face. For example, fear shows as widened eyes (the eyelids are open to the max). Anger would show as furrowed brows and a slight squinting of the eyes.

It is hard to describe how you can tell that there is intensity in someone’s eyes, as you just know it by looking at a face. I’m sure it has to do with small movements in the facial muscles and maybe the level of dialation in the pupils.

A look in their eyes.

A look in their eyes is that reflexive clenching of muscles in a certain way that translates a message without needed to talk. Those with empathy can pick it up easily.. and some people miss the obvious indications.

The hands send emotion in a similar way too.. A playful slap. a hurtful hit. a caress. a massage. a warming rub. a clench of fear. an angry shove. a comforting hold. a guiding certainty. a mischievous tickle. a sensual graze. a bear hug. a friendly hug. an uncomfortable hug.

another metaphor could be Maybe there is a sound to someone's voice when you know they are scared, or flirting, or angry.. or they have a tone to their voice that demands the room to be silent. You don't know why.. but the room quiets because everyone can sense it.

A look in their eyes is that kind of communications. A tonal change in minor facial muscles that subtly changes the message.