Anatomy of the eye
In order for eyes to be able to see, the cornea and the lens must refract the light entering the eyes and focus it on the retina (which is the layer of light sensitive cells lining the back of eye). The retina converts light rays into impulses, sent through the optic nerve to the brain, where they are recognized as images.
About 70% of the eye’s focusing power comes from the cornea and 30% from the lens.
Normal retina (the back of the eye) showing the optic disc and macula