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The cornea is the transparent front of the eye that covers the pupil, iris and anterior chamber. It is an important part of vision, refracting light along with the iris and anterior chamber and accounting for some two-thirds of the eye’s total optical power.
Its refraction is fixed, however, so we rely upon the lens to really bring things into focus. The cornea has a great deal of unmyelinated nerve endings and is therefore extremely sensitive, as anyone who has ever worn contact lenses can attest. Its transparency, coupled with an absence of blood vessels, make corneal tissue quite unique.