By Joy A. Dryer , Ph.D.
I. INTRO. Do you believe that intense romantic love can last a lifetime? OR, alternatively, do you believe that love naturally develops through phases? General phases such as the 3 that Margaret Mead is said to have defined: apparently she thought every woman needed three husbands: one for youthful sex, one for security while raising children, and one for joyful companionship in old age.
August is a good time to ask such long view questions. August is a kick-back month for many. Fewer folks in the office. Many on vacation. I hope you've taken a little time off from daily routines - maybe a few long weekends when you can kick up your feet and look at .... well ...along with a colorful garden...some beautiful view...... to look really look at your partner.
I'm here to tell you that mutual gaze with your partner is one way psychologists and neuroscientists have found you can know your partner more intimately, and help your passionate love last a lifetime.
Mutual eye gaze between you and your partner can help you learn to read, to understand, and to know one another better. Mutual gaze can help you feel more connected because it's emotionally arousing: your pupils dilate, the 'feel good' oxytocin neuropeptide releases. Try this exercise [3 minutes a night?] : you can use it to fight well. To soothe. To repair.
Here's the Gazing Exercise developed by Stan Tatkin, PsyD, founder of PACT [Psychobiologic Approach to Couples Therapy]. Gaze quietly into your partner's eyes. [Not meant to be a sexual activity.] You can lie in bed or sit in facing chairs, knee to knee. No need to talk or to touch: ok to laugh, cry, giggle, or have whatever emotion arises. Try not to control your face. You can avoid feeling self-conscious by pouring your attention over your partner's face: notice every detail ...changes in his/ her eyes, face, skin color, skin tautness, breathing, muscle tension. I.e. your focus is on the Other, not on your own internal shifts or feelings. Look and be seen, just as you are. Know and be known, just as you are.
No need to set a timer. But try to do at least 3 minutes. Afterwards, notice how you both feel. Closer? Or more distant? Uncomfortable at any point? Triggered by what? If discomfort resolved, how?
This exercise can be a constructive and fun tool to use in your relationship. Below I describe why mutual eye gaze is so effective in oh so many let-me-count-the-ways.
II. MUTUAL EYE GAZE: Here's lookin' at you Kid. Baby researchers since the 1970's  showed us how babies' intense gaze at their mothers [or fathers] is a crucial psychological process of finding out who they are, and how to be in relationship with another. Present day psychologists are using the same gaze to help couples to know and to relate better to one another.
III. OUR PUPILS: Consciousness and Our unconscious. Scientists say they can study consciousness by observing pupil size changes. I'd add, that pupillary action and mutual gaze reflects our unconscious too! because our pupils involuntarily respond to our emotions.
When we look at someone we love, the visual cortex at the back of our brain [occipital lobe] captures the actual image. An older part of the brain, the autonomic nervous system [ANS] , actually registers and responds to these incoming signals. Our ANS regulates, without our awareness or permission, the continuous tuning of our pupil size [along with other involuntary functions including our internal organs such as our heart rate, heart rate variation, and blood pressure].
Our pupil size reflects both the Sympathetic [the accelerator, the exciting] branch - dilating our pupils -- and the Parasympathetic branch [the brakes, the relaxing] - constricting our pupils - branch. In a healthy secure relationship, when we feel safe, we can regulate our arousal state, balancing between excitement and tranquility. This occurs when both these branches of our ANS are in a synchronized balance of movement and stillness, self-activation and self-control. When you do the exercise I describe above, you both will likely be in a balanced state of what Tatkin  calls "quiet alertness."
IV. PUPIL SIZE and OXYTOCIN: Gazing is exciting. In our social interactions with another, we need to make quick assessments whether we are in a safe or dangerous situation, or with a safe or dangerous person. It turns out that when your pupils dilate with interest, arousal, or excitement, oxytocin is released. This is the "feel good" neuropeptide, or hormone, that plays a central role in enhancing emotions, communicating, and socially approaching others.
A slew of studies used double blind methods in which they randomly gave either the placebo or Oxytoxin [ administered through the nose] to participants. Results significantly showed that compared to the placebo groups, the Oxytocin groups a) gazed longer and more frequently toward angry vs. happy faces ; b) showed increased number of fixations and total gaze time toward the eyes  ; c) showed increased ability to read emotion more accurately in the eyes in the RMET - Reading the Mind in the Eyes Test .[Google the RMET.]
V. ATTACHMENT and OXYTOCIN: We're connected. Using oxytocin as the positive indicator of attachment, neuroscientists have used fMRI techniques to show what parts of the brain are activated when a pair is gazing at one another. They've discovered that similar areas of the brain light up when studying mutual gaze between parent-infant pairs who are attached to one another, and adult pairs who are attached. Some of these brain regions, like the substantia nigra, globus pallidus, and thalamus showed a high density of oxytocin and vasopressin receptors. 
Both oxytocin and vasopressin as "feel good" hormones flag these areas as dopamine-rich areas of the brain. In turn, dopamine is the primary neurotransmitter of the feel-good circuit in the brain, associated with reward, motivation, and wanting. You "feel good" while gazing at your partner. So you continue the same approach behavior. This feels good so it reinforces the continued positive loop.
VI. MUTUAL EYE GAZE: Start here. Go! So mutual gaze is the entry point into that feel-good circuit loop. We all can learn to read and to know our partners well. We can use this exercise to fight well. To soothe. To repair. Both Stan Tatkin in his PACT work with couples, and Helen Fisher and her research colleagues believe that romantic love c a n last a lifetime. And, mutual gaze is one way to keep curious and knowing, to keep your relationship feeling novel and exciting.
SUM. Thus we've come full circle to understand that gazing at one's partner is an exciting event. Our pupils dilate automatically, out of our awareness. Because the "feel good" neuropeptide oxytocin [a chemical communicator, or transmitter] is released when stimulated by mutual gaze, you "feel good" while gazing into the eyes of your partner. Thus, you can use mutual gaze in numerous positive ways. The kids can be clamoring at the breakfast table, and a minute gaze across the table at one another can be a quiet connecting moment. You might be in the middle of a fight, and if one of you can remember to slow down, touch the other's arm and say, Hey! Lookin at you, Babe ! Stay for a moment, you could change the emotional interaction.
So try this mutual gaze with your partner: kick back.... stop time... and be known by one another with a few minutes of gaze. Enjoy. Here's lookin' at you, kid.
REFERENCES. In the interest of space, and the general public audience nature of this blog, I have not included a Reference list of the studies I've read:  Tatkin, S. 2011;  Stern, D. 1985, Beebe, B 2016; 3] Guastella, JA., Carson, DS. et al, 2008; (Guastella, JA, Mitchell PB, Dadds, MR, 2008;  Domes, G. et al, 2007;  Fisher, H.,1992; Acevedo, BP, et al 2011. If interested in specific references, email me at firstname.lastname@example.org. As always, I invite your comments to this blog. And follow me on Twitter @joydryerphd.