Updated: Jun 17
I sit. I see. Light falls. It reflects off objects and enters the eyes. The retina converts photons of light into electrical impulses that travel the optic nerves. The brain alchemizes these rivers of light into sight. It is wondrous.
Even though my mind may be agitated, my mood depressed, my thoughts fragmented, I can see. My eyes alight on colors. I perceive many shades. There are millions of receptors within the eye that detect light and color. I am aware of the empty space between me and the objects my eyes rest upon. Like a camera lens, the pupils contract and dilate, adjusting depth of field… with just a thought.
If the human eye were a camera, it would have over 500 megapixels. By comparison, the top digital cameras have between 102-200 megapixels. The human eye is the only multi-focus lens in the world which can adjust in milliseconds. I am hardly aware of the muscles that dilate or constrict the pupils of the eye or the muscles around the eye that move the eyeballs from side to side (even as I type this). I blink without thinking, but, in this moment, am aware. As awareness blossoms, my mind settles. A calm mind is a refuge.
Because I have sight, I can enjoy art, writing, photography, and reading among my other interests. With sight, you can take in the symbols we called letters and translate those into sounds, recognizing the serpentine letter s, the curved letter c, the crossed letter x, the dotted letter i. Combined with other letters and blended together, they produce words. Strung together, these words make sentences which grow to paragraphs which may evoke thoughts and emotions.
Because I have sight, I can toss a ball around with my sons. The brain processes millions of bits of information (e.g. the size, shape, and weight of the ball), calculates the ball's trajectory, estimates where the ball will land, coordinates with the motor cortex to move, to extend the arms and fingers, to catch. The gaze locks on to the target (e.g. the ball). Neurons in the parietal reach region of the brain inhibit eye movements to center on the target. The brain predicts, decides, and calculates my next movements in fractions of a second prior to execution. It has determined how much energy the body needs to move, to reach, to catch. If I drop the ball, with practice, the brain revises its predictions, makes micro adjustments to movements, adjusting as needed so that I can improve my performance. Is this not wondrous?
The eye processes thousands of bits of information every hour. Again, photons of light are converted to electrical signals that are sent to the visual cortex. 90% of the connections coming into the visual cortex, however, carry predictions from neurons in other parts of the cortex. Only a fraction of what we 'see" is raw, visual input. What we see is filtered with predictions, evaluations, memory, identification, language from other parts of the mind. In other words, we co-create what we see.
And what we create is often distorted. In a recent study published in the apex journal Nature, researchers found that visual perception at the retinal level changes to maximize personal advantage. Our cognitive biases are not just inaccurate judgments, but play an integral role in how we behave.
To cultivate the habit of mindfulness, you may find it enjoyable to dedicate each day to one of the senses this week. Today, I invite you to celebrate the gift of sight. Be like an artist- sensitive to colors, shapes, form, texture, shadows, space, contours, and the play of light. Rather than anticipating or labeling what you're seeing, see if you can go deeper, without naming, without trying to identify what is there, without assigning it meaning, without judging as "pleasant" or "unpleasant" "interesting" or "dull," or looking at it through the filter of past associations. Be curious and open. Marvel at the details. Approach sight with a beginner's mind, as if seeing for the first time.
When you sit to meditate, experiment with eyes open. Meditators also experiment with gaze to modulate brain activity. Brain activity slows down when we focus our gaze. The brain can switch between slow and fast integration of information, allowing it to modulate the timescales on which it operates. Different processes in the brain unfold at different timescales: While sensory input can be handled within tens of milliseconds, decision making or other complex cognitive processes may require integrating information up to several minutes. When a meditator focuses their visual attention or redirects it to a specific point in space, that changes the timescale of neural activity. There is a strong correlation between the present state of the brain and its state a moment ago. When the neurons are attending to something, they remember their own past activity better, and this implies a slower timescale.
Some techniques call for eyes closed, some for eyes opened. With eyes opened, one focuses on a narrow point as in the Zen tradition where practitioners gaze at a spot on a wall or as in the Shambhala meditation technique where eyes are opened and the practitioner holds a soft gaze angled about 45 degrees. In some Tibetan techniques, practitioners hold a broader, panoramic gaze and look out at the horizon. When the gaze is fixed, the eyes make involuntary movements called microsaccades. Microsaccades modulate the activity of neurons in the visual cortex and related architecture and play a role in attentional shift.
Our pupils respond to more than light. Pupil dilation correlates to central nervous system arousal. Stimulation of the autonomic nervous system's sympathetic branch, known for triggering "fight or flight" responses when the body is under stress, induces pupil dilation. Whereas stimulation of the parasympathetic system, known for "rest and digest" functions, causes constriction.
Interestingly, not only does the aperture, or size, of the pupil change, but the aperture of our experience changes as well. When we are relaxed, our gaze is panoramic; when we are stressed, excited, or alert, our gaze narrows. When our gaze narrows, our field of attention also narrows. And by experience, we know that when we are relaxed, thinking is often broader. We can see multiple perspectives when we relax our conceptual hold.
Breath can also change our cognitive, attentional, emotional, and internal states. How we breath, whether slow and rhythmic, fast, erratic, etc. affects our state... and pupil size as well as focus. In other words, if our internal state changes, our breathing changes, metabolism changes, heart rate changes, the aperture of the pupils change. This relationship is bi-directional. if I want to change my internal state, I can intentionally modulate the breath and change my gaze. Frame rate slows down or speeds up accordingly.
Contrary to popular belief, meditation is not just about settling in and relaxing. There are times when the mind is dull. We use breath and sight to stimulate the mind and arouse the sympathetic nervous system. If I hyperventilate, for example, then retain the breath, I trigger my sympathetic nervous system and release adrenaline and acetylcholine. Attention and focus narrow. If I meditate with eyes closed or open and fix my gaze on something either on the horizon or set a soft gaze on the floor, the training outcome will be slightly different.
Certain meditation techniques can be cognitively demanding. Pupil constriction also correlates to mental effort. Princeton University psychologist Daniel Kahneman showed several decades ago that pupil size increases in proportion to the difficulty of a task at hand. "The pupils reflect the extent of mental effort in an incredibly precise way," he asserted.
Interestingly, processing visual information leads to a reduction of activity in auditory areas, meaning we spend less energy processing the sounds in our environment. This works the other way around as well: when we attend to auditory information, we reduce our visual processing activity.
Our visual system is a lever by which we can shift not only attention but modulate emotions. What you see, as previously noted, is filtered, and how you see the world- as safe, as hostile, etc.,- affects your mood and state of mind. We select those visual inputs that conform to our mental schemas. Seek beauty and you may see colorful flowers growing in cracks of pavement, wispy cirrus clouds painted on a canvas of blue sky, and find much to marvel at and appreciate. Conversely, one's vision may be so distorted that they see only through lenses of fear.
By literally returning to our senses, we can give ourselves a brief respite from the drama of life. May your sight be clear and your mind be at peace.
First published 4/25/2020
Edited and reposted 4/12/2023