Which vision type operates primarily at night?

Scotopic vision is the type of vision that operates primarily in low-light conditions, such as at night. This vision relies on rod photoreceptors in the retina, which are sensitive to dim light and are more effective in darkness than the cone photoreceptors responsible for color vision and detailed sight used during daylight. As light levels decrease, the rod cells become more prominent in facilitating vision, allowing the eyes to detect shapes and movement in low-light environments.

Mesopic vision occurs in intermediate light levels, such as during dawn or dusk, when both rods and cones are utilized. Photopic vision is associated with well-lit conditions and is mainly driven by cone cells, which are crucial for color detection and high acuity vision. Daylight vision refers to vision under well-lit conditions, predominantly relying on photopic mechanisms.

Understanding the distinctions between these types of vision is essential for recognizing how human eyes adapt to varying light conditions, especially in aeromedical contexts where considerations for nighttime operations and visibility are vital.