Retinal Fatigue

Retinal fatigue is a temporary effect that alters the mind's perception of certain objects and patterns. It is caused by excessively stimulating the eye with a certain image, and the effects can be seen after shifting gaze to another surface.

Background

• Retinal fatigue refers to over-stimulation of the cone cells within the retina. Cone cells are the pigment cells that allow us to see colors. There are three types of cone cells. The different types are sensitive to red, green and blue pigments.

Function

• Retinal fatigue occurs when a person stares at a certain color, or a pattern of colors, for a particular amount of time. After staring at the colors, a person may imagine seeing a certain pattern, color or shape if he immediately shifts his gaze to a different object or a blank surface.

Applications

• Retinal fatigue is often exploited in optical illusions. After staring at an image containing solid colors for a certain amount of time, a silhouette of that image can be visible after quickly staring at a white surface. Using the same practice with other images, it is possible to see the original image, but in complimentary colors rather than the original colors.