Galvanopupillomotor reflex

The Galinopupilomotor reflex is the response of the pupils and iris to environmental stimuli. Under the influence of positive emotions or natural light, they expand, and under negative emotions, they narrow. This mechanism of involuntary facial reaction is widely used in advertising, films, photogenic makeup and other creative and applied areas. For example, through the so-called Harlequin effect - bright colors and