Which type of vision is characterized by lack of color perception and requires off-center viewing?

Scotopic vision is the type of vision that occurs in low-light conditions, where the illumination is too dim for photopic vision to function effectively. It is primarily mediated by rod photoreceptor cells in the retina, which are highly sensitive to light but do not convey color information. This lack of color perception is a hallmark of scotopic vision, as rods are more sensitive to shades of gray and do not respond to the wavelengths that represent different colors.

Additionally, scotopic vision requires off-center viewing because the distribution of rod cells is greater in the peripheral regions of the retina. When a person tries to see in low light, looking slightly away from an object enables better visibility, as it allows the light to fall on areas of the retina with a higher density of rods. This unique characteristic of requiring off-center viewing distinguishes scotopic vision from other types of vision, which have different capabilities and operational thresholds in varying lighting conditions.