The eye is one of our most important sensory organs, enabling us to orient ourselves within our environment. In terms of its structure and function, the eye can be compared to a camera lens: light rays pass through the transparent surface of the eye—the cornea—and through the pupil.
The size of the pupil, and thus the amount of light entering the eye, is regulated by the iris. The incoming light rays are then focused by the lens located behind it and projected onto the retina. There, the light is converted into nerve impulses, which are transmitted by the optic nerve to the brain. By combining the images from both eyes, we are able to achieve spatial vision.