Photoreceptors are specialized cells in the eyes that detect light and convert it into electrical signals. They are primarily found in the retina, the light-sensitive layer at the back of the eye. There are two main types of photoreceptors: rods, which are sensitive to low light levels and help with night vision, and cones, which are responsible for color vision and function best in bright light. These cells play a crucial role in vision by allowing us to perceive our surroundings. When light hits the photoreceptors, it triggers a chemical change that generates an electrical impulse. This impulse is then transmitted to the brain via the optic nerve, where it is processed into the images we see.