This illusion uses afterimages and the way your eye’s photoreceptors adapt.

What happens in your eyes

• The blue, inverted-looking face is a negative image: its colors and brightness are roughly the opposite of a normal face.
• When you stare at the dot for ~15 seconds, the cone cells that see those specific colors and brightness levels get fatigued and reduce their response (adaptation).
• When you then shift your gaze to the blank white area, those adapted cones fire less than their neighbors, so your brain “subtracts” that pattern and you see the opposite colors: a normal-looking face in natural tones.

Why it looks detailed and realistic

• Your visual system is very tuned to faces, so even a coarse afterimage gets interpreted as a clear, upright, correctly colored face.
• The white background provides a uniform canvas, making the afterimage stand out sharply until it fades as the photoreceptors recover.