Cross-section of the left eye. From left to right, the optic nerve (yellow), followed by the retina, the choroid all the way to the ciliary muscle, attached to the lens by suspensory ligaments (red pink), the sclera (light beige), in front of the lens, the iris (green) with the pupil in the centre and in front of the iris, the cornea which surrounds the anterior chamber filled with aqueous humour.