Which element of the eye is responsible for light sensitivity?

The rods in the eye are responsible for light sensitivity, which is crucial for vision in low-light conditions. They are highly sensitive to light and allow perception in dim environments, making them essential for night vision. Rods do not detect color, but they are adept at detecting varying levels of brightness, which helps our eyes adjust to different lighting conditions.

In contrast, the other structures play different roles. The pupil controls the amount of light that enters the eye, adjusting its size based on light conditions. The lens focuses light onto the retina, contributing to clear vision but not light sensitivity per se. Cone cells, while also important for vision, are primarily responsible for color perception and function best in brighter light conditions. Thus, rods are the key component for sensitivity to light.