What Is the Negative Picture Illusion?

A negative picture is the inverse of a normal, or positive, image. In a negative picture, areas that are white or light appear dark, and darker areas appear to be light. Usually, photo negatives are turned into positive images in a darkroom. But with the negative picture visual illusion, your visual system and brain can briefly create a color image from a negative photo.

How to Create the Negative Picture Illusion

To see the negative picture illusion:

1. Stare at the dots on the woman's face in the picture below for 30 seconds to a minute.
2. Turn your eyes immediately to the center X of the white image on the right.
3. Blink quickly several times.

You should see an image of a woman in full color, although only briefly. If you are having trouble seeing the effect, try staring at the negative image a bit longer or adjusting how far you are sitting from your computer monitor.

How the Negative Photo Illusion Works

How does this fascinating optical illusion (more properly called a visual illusion) work? What you are experiencing is known as a negative afterimage. This happens when the photoreceptors, primarily the cone cells, in your eyes become overstimulated and fatigued, causing them to lose sensitivity.

In everyday life, you don't notice this because tiny movements of your eyes keep the cone cells located at the back of your eyes from becoming overstimulated. But when you stare at the negative photo image for a long time, you are preventing these movements.

Opponent-Process Theory

According to the opponent process theory of color vision, our perception of color is controlled by two opposing systems: a magenta-green system and a blue-yellow system.

The color magenta serves as an antagonist to the color green, so that when you stare too long at a magenta image, you will then see a green afterimage. The magenta color fatigues the magenta photoreceptors so that they produce a weaker signal. Since magenta's opposing color is green, you then interpret the afterimage as green.

You can experience this yourself by finding or drawing a bold, clear image of a single shape that is magenta. Stare at it for at least 20 to 30 seconds, then look at a blank white screen or paper. You should see the same shape, but in green.

Negative vs. Positive Afterimages

In a negative afterimage, you see opposing colors. You can also experience a positive afterimage, in which the colors stay the same in the afterimage. To try this, stare at brightly lit picture, and then close your eyes. For just an instant, you will continue to see the image, even though your eyes are closed.

You might also experience a positive afterimage after looking at a very bright light that is in an otherwise dark environment (say, a flashlight in a dark room). Similar to a negative afterimage, a positive afterimage occurs when the cells in the eye are stimulated and begin to tire.

After the cells in the retina respond to light, they don't stop responding right away, so you continue to see the image. Researchers call this "retinal inertia."

A Word From Verywell

Optical illusions such as the negative picture illusion are fun activities to try. But they also reveal important information about how the brain and visual system work. Understanding how these illusions work can help us better understand how the eye perceives information and how the brain then interprets that visual data.