Why do ‘people in love' look into each other's eyes?

Well! The first clue of it lies in the oft-quoted lines from famous poem of Roy Croft that say… “I love you not only for what you are, but for what I am when I am with you”; but the actual answer lies in a beautiful secret of nonverbal behavior…- PW, Sandeep Atre, Motivational Trainer

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Human eyes are a marvel! They see, gaze, glance, blink, wink, stare, cry, and at the same time they are called ‘windows of the soul’ because they reveal a person’s mental and emotional state more clearly than any other bodypart can. And there is one part of it that holds the answer of our question – pupils.

Pupils appear like two black spots at the centre-positions of the eyes. These spots are openings that vary in size per the changes in light. In bright light, their size decreases to about two millimeters across, and when the light decreases their size increases to almost four times its size in the bright light.

But you know what? They are equally affected by emotional changes. They can dilate or constrict in their size per whether we like what we see. When something excites us, whether in positive sense like pleasure or in negative sense like fear, the pupils expand more than usual. And when we see something that is distasteful then they contract. Pupil-dilation correlates so much with emotional arousal that researchers use pupil size, or pupillometry, to investigate a lot of psychological phenomena like introversion, sexual orientation, sleepiness, depression, decision making, moral judgment etc. Thus, studying pupils has been a favorite with many – from Ad agencies to Casanovas.