aware of this phenomenon during my third year of optometric training, when prominent behavioral optometrist John W. Streff visited Southern College of Optometry. At the time, Streff was the director of vision research at the Gesell Institute of Child Development at Yale. He had become known for describing a constellation of visual symptoms that resulted from stress and that is now called the Streff syndrome. Shortly after he arrived, Streff was casually chatting with a group of students and a journalist in the student union when he asked, “Could I have a volunteer?” The journalist, a young man in his twenties, raised his hand.
Dr. Streff used a sophisticated piece of equipment called a retinoscope to shine light into the journalist’s eye so he could observe the reflection (or “reflex”) of light off the retina.
“I want you to imagine that you are playing tennis,” Dr. Streff said.
As the man imagined, Dr. Streff peered through the top of the retinoscope, his face about twenty inches from the man’s eyes. A few moments of quiet anticipation passed. Then Dr. Streff said, “You just hit the ball. . .there, you hit another one. . .and another one.”
He was joking, I thought. After all, how could Dr. Streff know when this journalist was imagining hitting a ball?
“There, you hit it. . .you hit it again,” Dr. Streff continued to announce.
The man began to laugh. We all began to laugh too, although we did not yet know why. Then the journalist exclaimed, “You told me what I was doing just before I did it in my mind!”
Although this may sound strange, in a recently published paper in the journal PLOS Biology, an international team of researchers suggests that a lag exists between seeing something and becoming aware of it. According to the new “time slice theory,” supported by previously published psychological and behavioral experiments, our brains process unconscious information in brief frames of time and then splice the frames together like a movie into what we perceive as a continuous flow of conscious information.
In essence, we do not experience stimuli when they actually occur but much later, relatively speaking, when we become conscious of them. Another way of saying this is that our eyes respond to light well before it is rendered into our conscious experience of life. As we become increasingly more aware of the “just noticeable differences” occurring within us and in the world around us, we respond to subtler and subtler aspects of life, eventually seeing what is invisible to others.
I did not realize it then, but Dr. Streff’s awareness was highly developed, allowing him to notice when the light emitted from his retinoscope fused with the light emitted from the journalist’s eyes, providing him insights the journalist was not yet aware of.
“Let’s do it again,” Dr. Streff said. The journalist continued to visualize a game of tennis.
“That was a forehand,” Dr. Streff said.
“Nice backhand,” he continued. “Oh, you just hit a lob,” and on the commentary went.
Blown away by the demonstration, we all started talking at once, asking question after question. That day it became clear to me that there was an aspect of vision that had nothing to do with eye exams or glasses. I had had many experiences during my life where I sensed something before it occurred. But I could not imagine, at the time, how by peering into someone’s eyes Dr. Streff seemed able to see what another person was imagining. I was so inspired that I offered to drive Dr. Streff everywhere he went during his visit so I could question him.
Soon after Dr. Streff’s demonstration, a six-year-old girl was brought to the college clinic because she was failing in school and was a bit clumsy. Her parents assumed poor eyesight was to blame. Like Dr. Streff before me, I used a retinoscope to peer into the young girl’s eyes. I watched her eyes as I put different strength lenses in front of them. The eyes of most patients usually reflexively change as different strength lenses change the appearance of the eye chart in front of them, but the eyes of this young girl were nearly static. Her eye reflexes were dull, and her eyes appeared dark, as if no light was getting in or out. She could not see, but there was no biological reason for her poor eyesight. No matter what prescription I tried, her eyes did not respond. It was as if nothing could touch her, and I began to wonder if she might have suffered a trauma that was clouding her eyesight.
Although I was just beginning my third year of optometry school, I had read in one of my textbooks that emotional issues could, at times, produce a temporary loss of vision termed hysterical blindness. It became clear to me that glasses were not going to help her, so I removed my white clinic jacket, sat on the floor, and did something I had never done.
“Do you know your letters and numbers?” I asked.
She said that she did.
“Great, then let’s play a game! I am going to use my finger to write a number on your back. I want you to tell me the number, okay?”
Lightly, with my index finger, I drew a number one. She seemed confused.
I turned around. “How about you do it to me? Draw a letter or a number on my back and see if I can guess what it is.”
By the end of that session I could already see a change. It was as if she opened a door and allowed me into her world. She trusted me because I helped her discover that she could see via her feelings rather than just her eyes. Her eyes seemed brighter, and she was already starting to guess the right letters and numbers. For a few weeks I continued to work with her in this way. By the end of the tenth session, I could draw three-letter words and double-digit numbers on her back, and she could guess correctly most of the time. She could track a ball with her eyes, walk on a balance beam, and see with 20/20 vision. It was obvious that she was seeing the world differently and so was I.
Later during my career, I began asking patients to complete different tasks as I watched their eyes. The patients read. They did math in their heads. They imagined. Initially, as expected, I noticed that the pupil would dilate and constrict in response to light, as if it was actually breathing. Here is what was not expected: I found that whenever people were exerting effort, their pupils shrunk and the light in their eyes became dull. It was as if “trying hard” induced tunnel vision and murkiness. When their efforts stopped, suddenly their pupils expanded and filled with light. It was dramatic, and it happened instantaneously because the pupil also responds to any sensory, emotional, or mental change occurring in the autonomic nervous system.
Having had difficulties with reading my entire life and continually being told to “try harder,” this discovery helped me see that we are designed to function with little or no effort. I was beginning to realize that our potential as human beings hinged on the subtle balance between striving and thriving. The photos below, taken within seconds of each other, illustrate the real-time changes observed in one child’s eyes.
Pupillary reflex during retinoscopy illustrates the difference between exertion and ease
Perhaps this is why the German word for eyesight is Augenlicht — literally, “eye light” — and why in Greek, the expressions “I’m losing my light” and “I’m losing my sight” are synonymous.
Having had the opportunity to work with that six-year-old girl allowed me to discover that a person’s emotional state is intricately linked to their eyes. Good feelings cause pupils to expand, allowing a greater amount of light to enter and exit the eyes. The light expands
