Final answer:
Photoreceptors are located in the retina at the back of the eye and include rods and cones, responsible for converting light into nervous impulses.
Step-by-step explanation:
The photoreceptors in the human eye are located in the retina. These key cells, which include rods and cones, are responsible for the transduction of light into nervous impulses. When light enters the eye, it first passes through the cornea and the lens. These structures help to focus the light on the retina. The iris, the colored part of the eye, functions to adjust the size of the pupil and thus regulates the amount of light that reaches the retina.
The retina is situated on the inner surface at the back of the eye and has a specialized area known as the fovea, which contains a high density of photoreceptors, providing sharp central vision. Additionally, light passing through the retina encounters ganglion cells and bipolar cells before reaching the photoreceptors. It's also worth noting that the cornea serves as a protective layer on the front of the eye, not the site of photoreceptor cells.