In practical terms, which visual system is best at low light detection?

The scotopic visual system is specifically adapted for low light conditions, which makes it the most effective system for detecting light in dim environments. This system relies predominantly on rod photoreceptors, which are highly sensitive to low light levels. Rods are more numerous than cones in the retina and are concentrated in the peripheral regions, allowing for better vision in darkness.

In contrast, the photopic system utilizes cone photoreceptors, which are responsible for color vision and function optimally in bright light conditions. Cones require higher levels of illumination to activate, making them less effective in low light situations.

The scotopic system's ability to detect light at low levels is due to the biochemical properties of rods, which can respond to single photons of light, enabling humans to see in near darkness. This sensitivity is a crucial component of the scotopic system’s function, setting it apart from the photopic system in terms of low light detection capabilities.