What part of the eye contains photoreceptor cells?

The retina is the part of the eye that contains photoreceptor cells, specifically rods and cones. These cells are crucial for converting light into neural signals, enabling vision. Rods are responsible for vision in low light conditions and do not detect color, while cones are active in brighter light and are responsible for color vision and high spatial acuity. The retina, located at the back of the eye, works as a screen that captures light and initiates the process of visual perception, sending the information to the brain via the optic nerve.

Understanding the roles of the other parts of the eye reinforces why the retina is the correct answer. The cornea primarily functions to refract light and begins focusing it, the iris controls the size of the pupil to regulate light entry, and the sclera provides structural support and protection to the eyeball. While all these components are integral to vision, it is the retina that specifically houses the photoreceptors necessary for detecting light and allowing sight.