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Acquired Control of Pupillary Responses

Milton H. Erickson

Estimated reading time: 5 minutes, 34 seconds.

Reprinted with permission from The American Journal of Clinical Hypnosis, January 1965, 7, 207-208.

An eight-year-old girl with a marked visual defect in one eye and a strabismus of that eye was under the care of an ophthalmologist. He had prescribed various eye exercises and the wearing of an eye-patch over the stronger eye to correct the suppression of vision in the weak eye. The girl performed her exercises faithfully, sitting in front of a mirror so that she could see what she was doing. During the course of therapy she became much interested in her pupils and soon discovered the papillary responses to bright and dimmed lights. Since she was an excellent somnambulistic hypnotic subject and had had extensive experience with suggested visual hallucinations, some of which she intentionally remembered subsequent to arousal from the trance state, she became greatly interested in watching her eyes while ”I thought different things.” The wearing of the eye-patch was “thought about,” and she watched the pupils of her eyes as she did this “thinking.” She would “think about” bright lights, semidarkness, and visual hallucinations close m her eyes and far off in the distance. She became markedly aware of the difference in the visual acuity between her eyes, and she would hallucinate an eye-patch over her eye. She learned to dilate and to contract her pupils at will. Then she became interested in unilateral papillary responses. This, she explained, was harder to learn, therefore more interesting. To accomplish this she “imagined” wearing an eye-patch and seeing with only the weaker eye. Then, undoubtedly aided by the learnings affected by the suppression of the vision in the weaker eye, she “imagined” seeing with only the normal eye while she “stopped looking” with the weaker eye. This uniocular effort of hers may also have been aided by a possible central fusion defect, which the ophthalmologist had suggested as distinctly a possibility during his first studies of her vision. In furthering uniocular behavior the girl had called upon her hypnotic experience to hallucinate a patch over one eye and a bright light in front of the other. There were variations of this, such as “imagining looking at something close by with one eye and at something else far away with the other,” an item of behavior highly suggestive of the accomplishment of students who learn to look through a microscope with one eye while using the other in reading or sketching.

When it came time for a reexamination of her eyes, she sat demurely in the chair while the ophthalmologist proceeded with the task. After an initial look at both eyes, he made a careful study of the right eye, making notations of pupillary size and of other findings. Then he turned to her left eye and was startled to see the pupil widely dilated. He glanced hurriedly at the right eye and then made an intense, searching examination of the left eye, carefully recording his findings including pupillary measurements. Then he leaned back in his chair to study and compare the separate data he had noted. Much puzzled, he glanced reflectively at her eyes and was again startled, this time because both pupils were equally widely dilated. He promptly reexamined the right eye, discovering nothing new except the dilation of the pupil. Again he studied his notations and again looked up to find that the right pupil was this is a dilation of the pupils particularly in the somnambulistic state still dilated but that the left was markedly contracted.

His facial expression of astonishment and bewilderment was too much for the little girl, and she burst into giggles, declaring, “I did that.” “But you can’t, nobody can,” was his reply. “Oh yes I can, you just watch.”

Thereupon she demonstrated bilateral and unilateral pupillary behavior, doing so in accord with specific requests from him. She explained to him, “All you have to do is look in a mirror and see your pupils and then you imagine you are in a trance and then you imagine looking at different things. You can look at different things that you imagine with one eye and at something else with the other, like looking at a bright light with one eye and the clouds in the sky when it’s almost dark with the other, and you can look at things far off and right close by. You can imagine a patch over one eye and just seeing with the other. You can imagine all kinds of different things to look at in different kinds of ways with each eye.”

Years later, at a seminar on hypnosis where she was present, this matter of pupillary control was mentioned. Several physicians challenged the possibility. Upon their request she obligingly demonstrated. At the time of the writing of this paper she was asked to read it for possible alteration s or additions. When she finished, she remarked, “I haven’t done that for years. I wonder if I can do it now.” She began reminiscing about the framed mirror into which she had gazed, the overhead light she had used, the window beside which she had sat, and as she did so she demonstrated retention of her original skill. She also added the comment that she could still, as she remembered doing previously, feel the contraction of the pupil, although the dilation as such was not felt. She could not explain better than to say, “You  just feel something happening to that eye, but you cannot name the sensation.”


 At first thought, one would not think this sort of pupillary control possible, until reflection brings to mind the ease with which a conditioned response can be induced by a related light-sound stimulus, the evocation of the papillary response by the sound stimulus alone, and then a reconditioning of the pupillary response to a   related sound-tactile stimulus with the papillary response then being elicited by the tactile stimulus alone, etc.

Also, undoubtedly important is the fact that many hypnotic subjects manifest  altered  papillary  behavior  in  the   trance state. Most frequently this is a dilation of the pupils particularly in the so somnambulistic state and the pupillary size changes when visual hallucinations are suggested at various distances. There are also pupillary changes that accompany suggestions of fear and anger states, and of the experience of pain. Also pertinent is the fact that this young girl was later discovered to be remarkably competent in developing autohypnotic trances to obliterate pain, disturbing sounds when studying, and to  establish  hyperacousia when background noises interfered with her normal hearing

In brief summary,   the report indicates that papillary responses ordinarily regarded as reflexes not accessible to voluntary control are, in fact, subject to intentional control.