What is the peak sensitivity of the scotopic luminous efficiency function?

The peak sensitivity of the scotopic luminous efficiency function, which describes how the human eye responds to dim light levels, occurs at approximately 507 nm (nanometers). This peak is primarily associated with the function of the rod photoreceptors in the retina, which are more active in low-light conditions, perceiving shades of gray and enabling night vision.

In the context of visual perception, rods are the cells that enable us to see in low-light environments, and they are particularly sensitive to wavelengths around the 507 nm mark. This sensitivity allows for optimal visual performance under scotopic (dim light) conditions, highlighting the efficiency of rod cells in processing light rather than colors.

While there are other wavelengths provided in the choices, such as 480 nm, 550 nm, and 600 nm, each corresponds to different aspects of photopic (daylight) vision or the vision mediated by cone cells. The rods, due to their higher sensitivity to shorter wavelengths around 507 nm, play a critical role when light levels drop, therefore making 507 nm the peak sensitivity point for scotopic vision.