Illumination edge is defined as the border between two (2) areas created by different light intensities in the two (2) areas.

The term "illumination edge" is not a commonly used term or concept in psychology. However, the idea of different light intensities affecting our perception and behavior is studied in the field of environmental psychology.

For example, researchers have found that the amount and quality of light in indoor environments can have an impact on our mood, productivity, and overall well-being. In an office setting, having access to natural daylight or well-designed artificial lighting can improve employees' mood and performance. Conversely, poor lighting or insufficient light can contribute to fatigue, eyestrain, and headaches.

The concept of illumination edges may be relevant in certain contexts, such as visual perception or architectural design. For example, an architect may use varying light intensities to create visual interest and depth in a building's design. In terms of visual perception, the point where two areas with different light intensities meet could create a visual border or edge that draws the viewer's attention. However, more research would be needed to fully explore the implications of illumination edges in these contexts.