An experiment with the LED sensor of an Arduino, linked to Processing graphics.
inverted pulsating cat’s eye
When the light is high, the pupil of the cat’s eye widens,
when the light is low, the pupil of the cat’s eye closes.
[I know in reality, it’s the other ways round… ;) ]
--> The color of the pupil also changes, from bright (high value) to dark (low value).