Photoreceptor cells are specialized cells in the eyes that detect light and convert it into electrical signals. There are two main types of photoreceptors: rods and cones. Rods are sensitive to low light levels and help us see in dim conditions, while cones are responsible for color vision and function best in bright light. These cells are crucial for our ability to see the world around us. When light hits the photoreceptors, they trigger a series of chemical reactions that send signals to the brain. The brain then interprets these signals, allowing us to perceive images, colors, and movement.