Cornea

Sensory (eye & ear)OrgansHeadLeft and right

View left in 3D View right in 3D

What it is
The clear, dome-shaped window at the front of the eye. It has no blood vessels and is kept transparent by the regular spacing of its collagen fibres and by its pumping endothelium.
Function
Provides about two-thirds of the eye's focusing power (~43 dioptres) and protects the front of the eye.
Size
About 11.5 mm wide (horizontal), central radius of curvature 7.8 mm, 0.55 mm thick centrally and ~0.7 mm at the edge.
Clinical note
One of the most densely innervated tissues in the body, so a corneal scratch is intensely painful; LASIK and PRK reshape it to correct refractive error.

Nearby sensory (eye & ear) structures Anterior chamber (aqueous humour), Ciliary body, Corneoscleral limbus, Crystalline lens (cortex), Iris, Lens capsule, Lens nucleus, Pupil, Schlemm's canal, Zonular fibres (suspensory ligament of the lens)