Scientists have found that a 23-year-old German student can dilate and contract his pupils on his own. The feat until then was considered unprecedented by medical literature in the world.
The case was published in the International Journal of Psychophysiology. The study came to the conclusion that the student, identified as “DW”, is able to control his pupils after submitting them to a series of tests. None could verify whether the volunteer dilated or contracted by an indirect action.
In one of the tests, researchers measured the skin’s electrical properties by applying voltage to test whether it was being influenced by increased mental effort, which may also have increased pupil size indirectly. The result indicated that it was not.
The study found that “DW” can dilate pupils up to 0.09 inches (2.4 millimeters) in diameter and constrict them to 0.03 inches (0.88 mm) in diameter.
Using a type of brain scan, the researchers found an increase in the activation of certain parts of the brain involved in volition, or the student’s ability to decide and do something of their own volition.
Scholars reached out to the student after he himself reported the feat to Christoph Strauch, senior author of the experiment and assistant professor of the experimental psychology department at the University of Utrecht in the Netherlands. It was DW who sought out the researcher.
The student discovered the ability around the age of 15 or 16. He commented to the researchers that, to change the size of the pupil, all you need to do is focus on the eye, without having to expose yourself to a light or dark environment or any other situation that causes dilation.
“This makes DW different from other people who have demonstrated the ability to change the size of his pupils. What’s more, he can feel pupil muscles directly “it’s surprising, as it was thought to be impossible,” Strauch told the Live Science website.
Researchers say that more people can have the same feat. Anyone who believes they have the ability can contact the team via email: [email protected]