Final answer:
The retina is the part of the eye responsible for receiving and transducing images formed by the cornea and lens. It contains photoreceptive cells, especially concentrated in the fovea for sharp vision, but also has a blind spot where the optic nerve connects. The cornea, lens, and iris work together to focus light and regulate its entry into the eye.
Step-by-step explanation:
The retina is the nerve tissue located at the back of the eye, which receives the image formed by the cornea, the pupil, and the crystalline lens. This light-sensitive layer contains photoreceptive cells that are responsible for the transduction of light into nervous impulses. Since the retina receives the focused image, it is essential for vision; the densest concentration of photoreceptive cells is in the fovea, which provides the sharpest visual acuity. However, there is also a blind spot on the retina where the optic nerve connects, which lacks these photoreceptors.
The cornea and lens function together to refract light to focus it onto the retina. The lens's power is adjustable, enabling the eye to alter focus for seeing objects at different distances, with ciliary fibers and muscles changing the lens's shape as needed. The iris, which forms the colored part of the eye, regulates the amount of light entering through the pupil, contracting in bright light and dilating in dim light conditions.