The nervous tunic of the eye, also known as the retina, contains two primary types of photoreceptors: rods and cones.
Rods are photoreceptors that are highly sensitive to light and are primarily responsible for vision in low-light conditions. They are more numerous than cones and are concentrated in the peripheral regions of the retina. This sensitivity allows us to see in dim lighting and aids in night vision, but rods do not provide color vision.
Cones, on the other hand, function best in bright light and are responsible for color vision. They are concentrated in the fovea, the central part of the retina, which provides sharp central vision. Cones are essential for detecting fine detail and are divided into three types, each sensitive to different wavelengths of light, corresponding to the colors red, green, and blue.
In summary, rods facilitate our ability to see in low light, while cones enable us to perceive colors and fine detail in well-lit conditions.