What is the main function of the retina?

The retina plays a crucial role in the visual system, serving as the light-sensitive layer at the back of the eye that converts light into neural signals. This conversion process is essential for vision, as it enables the photoreceptor cells (rods and cones) in the retina to detect light intensity and color. Once this light information is captured, it is translated into electrical impulses that are transmitted to the brain via the optic nerve, allowing for visual perception.

Understanding the retina's function highlights its importance in the overall process of sight, distinguishing it from the other options. The retina does not focus images—that role is primarily fulfilled by the lens. Also, while the eye is protected by various structures, such as the cornea and eyelids, the retina itself does not provide protection. Producing tears is a function associated with the lacrimal glands, not the retina. Thus, the correct answer clearly indicates the primary function of the retina in vision.