![one pupil dilated one pupil dilated](https://media.sciencephoto.com/image/m1550539/800wm/M1550539-Dilated_pupil.jpg)
In one test, the researchers measured the electrical properties of the skin by applying voltage to test whether he was aroused by increased mental effort, which also might have increased his pupil size indirectly. indeed had this ability - and they found no indication that he was changing the size of his pupils indirectly. Through a series of tests, the researchers confirmed that D.W. What's more, that he can feel the muscles in the pupils directly "is astonishing, as it was thought to be impossible." How rare is this? different from other people who have demonstrated the ability to change their pupil size, Strauch told Live Science. He told the researchers that, to change his pupil size, all he has to do is concentrate on the eye he doesn't have to imagine a bright or dark environment.
One pupil dilated how to#
At first, he would change his pupil size by focusing in front of or behind an object, but with practice, he learned how to do it without focusing on objects.
![one pupil dilated one pupil dilated](https://images.ctfassets.net/u4vv676b8z52/6OIvXcHg59H1AzU67kdv1f/84b097176cdcaf97567cffdd568cbaf5/dilated-eyes-donts-hero-compressor.jpg)
"Constricting the pupil feels like gripping, tensing something making it larger feels like fully releasing, relaxing the eye," D.W. didn't notice that he had this ability until he played computer games for long periods of time. told Strauch and his colleagues at Ulm University. "I showed a friend that I can 'tremble' with my eyeballs, and he noticed that my pupils became small," D.W. realized that he could change the size of his pupils. When he was about 15 or 16 years old, the young man - identified in the case report by his initials, D.W. (Strauch was previously a doctoral student at Ulm University). But no one thought it was possible to change pupil size by directly controlling it like a muscle - that is, until a student of psychology at Ulm University in Germany contacted Strauch after taking one of his courses.