Which structure of the eye contains photoreceptors?

The retina is the correct answer because it is the layer at the back of the eye that contains the photoreceptors known as rods and cones. These specialized cells are crucial for converting light into neural signals that the brain interprets as visual images. Rods are responsible for vision in low light conditions and are highly sensitive to light, while cones are responsible for color vision and function best in brighter light.

In contrast, the cornea serves as the clear, outer structure that helps focus light as it enters the eye, but it does not contain any photoreceptors. The lens, located behind the iris, helps to focus images onto the retina but also lacks photoreceptive cells. Finally, the iris is the colored part of the eye that regulates the amount of light entering through the pupil, but it does not participate in the process of light detection. Therefore, it is the retina that is specifically designed to receive and process light information, making it essential for vision.