What is the inner coat of the eye that acts as the main receptor for light stimuli?

The inner coat of the eye that serves as the primary receptor for light stimuli is the retina. The retina is a thin layer of tissue located at the back of the eye that contains specialized photoreceptor cells known as rods and cones. These cells convert light into electrical signals, which are then transmitted to the brain via the optic nerve, enabling the perception of visual images.

Understanding the function of the retina is fundamental to grasping how vision works, as it plays a crucial role in detecting light and color, facilitating our ability to see in various lighting conditions. This makes it clear that the retina is indeed essential for the conversion of light stimuli into nerve impulses that the brain interprets as visual information.

As for the other structures mentioned, the sclera is the tough outer layer of the eye that provides structure and protection. The iris is responsible for controlling the size of the pupil and the amount of light that enters the eye, but it does not participate in light detection itself. The cornea, while it plays a critical role in focusing light onto the retina, is not involved in the actual reception of light stimuli. Therefore, the retina is definitively the correct answer in this context.