Which part contains photoreceptor cells that convert light into neural signals?

• A. Retina
• B. Cornea
• C. Iris
• D. Lens

Answer: (A)

Photoreceptor cells that convert light into neural signals are located in the retina, the light-sensitive layer at the back of the eye. The retina contains rods (for low-light vision) and cones (for color and detail). When light hits these cells, it triggers photochemical changes that alter their electrical activity, producing neural signals that travel through retinal neurons to the optic nerve and onward to the brain. The cornea, iris, and lens are involved in focusing and regulating light entering the eye, not in phototransduction, so they do not contain photoreceptor cells.