It’s undoubtedly true that eyes are windows of soul. Poets have lot more to mull over them than us. Eyes not only collect visual information from outside world but also express emotions and feelings. An eye is crucial sensory organ for any creature that got evolved with it. Biological making of eye is more complex when compared to some parts of brain. In fetal stage, eyes start taking shape before any others facial features do.

Eye contact is an inevitable part in face-to-face communication. Basically, looking at the other person can be anything like attracting or getting attracted, sympathizing, respecting, surrendering or dominating, interfering, interrogating, invoking, threatening, attacking and stopping or permitting to enter into private space depending upon facial expressions, neck position, gestures and postures.

Elongated eye contact received from others sparks neural pathway that triggers primitive defense mechanism and it prepares our body for an emergency. We have to decide either to approach or back off from person who is looking at us. Generally, we restrain long lasting gaze at strangers to avoid aggression or reprisal since they are not fully aware with our nature, intentions or motives until getting enough acquainted. In close relationships, reasonable eye contact is the key for retaining mutual interest, sympathy, confidence, and trust. At initials stages of courtship, only eye contact regulates the direction and progress of relationship formation.
We commonly experience that a steady gaze with non-threatening facing expressions like smile, titled neck, and slightly raise eyebrows with wide open eyes are irresistible interest invoking gesture. Batting of eyelid by other person standing or walking at distance from you clearly signifies that person has noticed you presence through peripheral (secondary) vision. Batting an eyelid is an unconscious expression of submission, respect or interest in stranger or person we know. This is a genetically hardwired social ritual for letting others feel secure and comfortable while confronting face-to-face or sighting alongside. However, an accidental and short lasting gaze or glance should not be considered as signal of attraction or hostility.
Pupils get automatically dilated when subconscious mind (limbic brain) finds someone or something worth interesting or attractive. On the contrary, pupils get contracted when aggression, anger, and hostility takes control of mind. Physiologically, pupil dilation is also subjected to amount of light it receives. Pupils dilate in darkness whereas they contract in bright light. Restaurant or coffee shop owners allot low illuminated areas that creates a romantic environment for couples. Actually, candle light dinner is an illusionary effort to induce attraction or affection since pupils automatically dilate receiving low light. Our brains are hardwired to make us get attracted to a person (of an opposite sex) with dilated pupils.

Gaze held at the line of sight and comfortably meeting with others' eyes symbolizes social - open approach whereas gaze hovering on face or body parts below it symbolizes personal approach or reserved - intimate feelings. Unsteady gaze might be subjected to uncertainty or inability to regulate emotions.

Women are more comfortable with considerably steady eye contact since they are more sympathetic, social - diplomatic and seek security and assurance from others. Many men feel uncomfortable or nervous to meet eyes with women that might generate feelings of insecurity, distrust, and uncertainty in women. Men like males of most other animal species are guardians of their own geographical territories and use to remain in social hierarchy hence mostly avoid direct eye contact until it’s friendly or it becomes necessary.