What It Means If Your Pupils Dilate When You Look At Someone

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eye with a dilated pupil

Pupils are the black circles located in the center of your iris, or the colored part of your eye. The pupil allows for light to enter your eye and often changes in size.

When your pupils appear larger, they're dilated.

Why do your pupils dilate when you look at someone?

The most common reason for pupils to dilate is dim lighting. Your eyes will dilate in order to allow more light to enter in a dark setting.

Similarly, your pupils will get smaller in brightness to prevent excessive light from entering the eyes.

However, there are several other reasons your pupils may dilate.

According to Gary Heiting, OD, pupils may dilate due to medications, eye injury, brain injury or disease, recreational drug use, and even sexual attraction.

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Dilated pupils may be a sign of attraction.

According to research, the iris muscles that determine when your pupils dilate are controlled by the autonomic nervous system which is responsible for uncontrollable reactions.

In some cases, dilated eyes are an involuntary response to sexual attraction and arousal.

When your nervous system is stimulated, your body releases various hormones depending on whether you are experiencing lust, attraction, or attachment. While lust is driven by a strong sexual desire, attraction and attachment encompass a strong emotional relationship or interest to someone.

Research suggests that eye contact is essential in human interaction and changes in emotion can cause dilation.

For example, in a 2012 study [1], 325 men and women were recruited to watch erotic videos as their pupil size was monitored. The study found that erotic videos led to pupil dilation among both sexes. This means that viewing images, videos, or seeing someone you like or find attractive in person can cause pupil dilation.

This pupil dilation may in turn play a part in who we pursue romantically, according to a 1975 study[2] that found that men found women with larger pupils more attractive. The men in the study described women with larger pupils as more feminine and soft, while women with smaller pupils were considered cold or hard.

This may be because we are hardwired to understand that dilated pupils equate to attraction, so the men were more likely to find attractive the women whose eyes were signaling that they were also feeling that attraction.

Dilated pupils may also be a sign of love.

The hypothalamus of the brain, which is involved in our reward pathway, affects love. The hypothalamus produces and releases dopamine when you do things you enjoy, including spending time with someone you love.

The hormones dopamine and norepinephrine are also released when we're attracted to someone and are what makes us excited and euphoric.

Similarly, oxytocin, also known as the “cuddle hormone,” is released from the hypothalamus during the attachment stage of a relationship, which is a large factor in long-term relationships and intimacies. According to Katherine Wu, large levels of oxytocin are released during precursors to bonding[3] such as sex and childbirth[4].

Each of these “love hormones” enhances pupil dilation, meaning that your pupils are likely to dilate when you look at someone you love.

RELATED: 9 Signs Of Unspoken Mutual Attraction Between Two People

Other physical signs of attraction

Pupil dilation (or a lack thereof) isn't the only sign of attraction.

Since there are several emotions and events that can influence one's pupil size, you must also look for nonverbal cues to see if someone is attracted to you.

Some of the most common body language signs of attraction include these:

1. Mutual eye contact

Pupil dilation isn't the only important aspect of eye contact. If someone is attracted to you, they're more likely to make eye contact with you more often and also hold it for longer.

2. Increased touching

A 1992 study[5] found that touch leads to increased attraction.

3. Mirroring

A 2008 review of three previous studies[6] found that people are more likely to mirror (or mimic) people they find attractive. Each of these can be categorized as an act of engagement, often used when someone is attracted to you.

RELATED: Who Falls In Love Faster: Men Or Women? The Secrets Of Attraction, Revealed

Sydney Taylor is a writer who focuses on love, news and entertainment.