Bera Theory

The Beer theory (named after the German ophthalmologist Max Beer) describes the ability of the visual apparatus of humans and other animals to respond to changes in illumination. The ability to visually adapt is a natural physiological mechanism that allows us to adapt to changing environmental conditions. The eyes respond to changes in ambient light and adjust perceptual settings such as brightness, contrast, and color perception. Thanks to this process, we can see better under bright or dim light sources, in the dark or in bright sunny conditions.

Beer's theory can be divided into two stages: reflexive and adaptive. The reflex theory implies that visual adaptation occurs due to the physical reaction of the eye to changes in light-sensitive cells, and the adaptation theory believes that adaptation occurs due to changes in neuronal activity and adjustments in perceptual settings.

The first to propose Beer's theory was the German scientist Otmar Kohlsheimer. He proposed that light-sensing cells operate relatively independently of each other and respond faster to changes in light than the time delays in nerve signals to the brain. This concept was further developed by Max Beer, who developed a more complex theory that explained the mechanism of adaptation to changing illumination and included the reaction speed of parts of the visual system along with the activity of neurons.

In 2011, British researchers supplemented this theory, proving that this brain reaction is indeed associated with the activity of neurons in the reticular formation. It not only increases the brightness of the image, but also adds color to it.