New optical illusion. One side of the image shows a negative of a woman`s face, while the other is a solid color background.
The optical illusion is based on a phenomenon called `afterimage`. Eye photoreceptors detect colors and encode them in a way that our brains can understand. Humans have several color channels: shades of gray, red and blue, and also blue and yellow, which allow us to encode colors in any environment. When we look at one color, the color channel cells become more active. After some time, the cells get tired and the activity decreases.
For example, if you stare at something yellow for a long time, you stimulate the yellow and blue color channel cells. When you then look at a uniform color wall, like gray, after staring at yellow, the cells are in a resting state. The yellow code relaxes, and the opposite color code becomes stronger, so you see blue. In the illusion, our blue cells - receptors get tired and their activity decreases, which stimulates the opposite color - yellow. This allows us to see a more natural skin color and the inverted image.
