The image of an object is formed on the retina after passing through the lens, which, depending on the distance of the object, expands or contracts to give a sharp image.
Inner membrane at the back of the eye covered in light-sensitive nerve cells (photoreceptors); these transform light into an electrical impulse that is carried to the optic nerve.
Line along which light emanating from an object propagates. The retina converts light rays into nerve impulses, which are then interpreted by the brain.
