What role do photoreceptors play in vision physiology?

Photoreceptors play a crucial role in vision physiology by stimulating electrical impulses in response to light. Located in the retina, the two main types of photoreceptors—rods and cones—are responsible for capturing light photons and converting them into electrochemical signals. Rods are highly sensitive and allow us to see in low light conditions, while cones enable color vision and function best in bright light.

When light hits these photoreceptors, it triggers a biochemical process that changes the electrical charge across their membranes, leading to the generation of a neural signal. This signal is then transmitted to bipolar cells and ganglion cells before being sent to the brain for interpretation as visual information. This fundamental ability to transform light into neural signals is essential for all visual processes, including recognizing shapes, colors, and motion.