The sclera forms the outermost layer of the eye; it is “the white of the eye” that can be seen from the outside around the pupil and iris. It is therefore also called the white eye membrane. Known in Latin as the “sclera,” it protects the eye from external influences and ensures that it maintains its shape.
The sclera is tensioned by intraocular pressure and encloses almost the entire eyeball: on the surface of the eye, it transitions into the transparent cornea and opens at the back at the optic nerve. Furthermore, the eye muscles that move the eye are attached to the sclera. The white sclera makes eye movement and gaze direction recognizable in humans—making it an important component of non-verbal human communication.