In terms of anatomy,
the human pupil can dilate or contract 6 to 7 times within tens of milliseconds under intense mood changes like ecstasy, excitement, or sadness.
This is the organ most closely linked to mood in the human physiological structure, and it does not change according to subjective human will.
Even those who have undergone professional anti-interrogation training and can control subtle facial muscles to achieve a state of "thunder in the chest, but a calm lake on the surface" in micro-expression management.
Their pupil changes can still clearly reflect the fluctuations of their inner emotions.
Eyes are the windows to the soul,
and the Western painting school has always valued people's eyes highly.
The eyes that can express a character's state of mind, the mirror that can portray complex merging of spatial structures, and the light and candlelight that can depict color and shadows.
