Animation of the structure of the human eye. Starting with a 3D model showing the eyeball white, iris blue, pupil black and eye muscles red, it zooms in to a 2D cross_section. This shows light grey beam being focused by the cornea far right and then the lens grey oval, coming to focus on the back of the eye. Zooming in further, the back of the eye is lined with the light_sensitive retina. In the middle of the retina is the macula, the region of the retina with the highest density of colour_sensitive cone cells. This is the area responsible for sharp central vision.