I know this is cliche, but speaking from personal experiences I do have to concur that our eyes are the windows to our souls. When you’re speaking to a person face-to-face, are they looking at you while you speak, often rubbing their eyes, or looking in other directions?
Eye-rubbing, blinking, and squinting are common gestures of shielding the eye and it’s a signal that the person is feeling uncomfortable. Whenever someone performs this gesture, it normally indicates that the person you’re talking to is disagreeing with what they are hearing or seeing.
Another fun fact is that your pupils actually dilate when you see something pleasant or stimulating (like when I know I’ll be having pizza for dinner). Vice versa, when the stimuli is something negative or uncomfortable, your pupils tend to contact and block out the unpleasant imagery.
Additionally, one of the more popular eye-reading assessments are eye directions. To summarise, a right-handed person would usually look up and to the left when they are recalling a memory, and look up to the right when they are lying to delve into their imaginary side of the brain. But don’t keep staring at the person you’re talking to when you’re assessing their eye directions!