The cornea is the clear, transparent front layer of the eye through which light passes. The iris gives our eyes colour. The pupil is the black hole within the iris, which acts like the aperture of a camera, enlarging in dim light and contracting in bright light.
The lens helps to focus light on the retina.
The retina is the innermost layer of the back of the eye. This layer of light-sensitive nerve endings carry the visual impulse to the optic nerve. The macula is the central zone of the retina, which provides our most central, acute vision. The optic nerve conducts visual impulses to the brain from the retina.