Which type of photoreceptor is specialized for nighttime vision?

Rods are the photoreceptors in the retina that are specifically specialized for low-light conditions and are crucial for nighttime vision. They are highly sensitive to light, allowing for vision in dimly lit environments, making them essential for seeing in the dark. Rods do not perceive color and are primarily responsible for detecting brightness and movement, which is why they excel in nighttime or low-light situations.

In contrast, cones are the photoreceptors responsible for color vision and function best in bright light, making them less effective in dark conditions. Bipolar cells and ganglion cells are part of the neural circuitry of the retina that process and transmit visual information but do not directly sense light. Therefore, rods are the correct choice for nighttime vision due to their unique adaptation to low-light environments.