Rod cells are specialized photoreceptor cells found in the retina of the eye. They are responsible for vision in low-light conditions and are highly sensitive to light. Unlike cone cells, which detect color, rod cells help us see in shades of gray, making them essential for night vision. Each human eye contains about 120 million rod cells, primarily located in the peripheral regions of the retina. They contain a pigment called rhodopsin, which enables them to absorb light. This ability allows us to detect movement and shapes in dim environments, contributing to our overall visual perception.