Write the function of the following part of human eye: Cornea.

Light enters the eye through a thin membrane called the cornea. The cornea helps to shield the rest of the eye from germs, dust, and other harmful matter. The cornea acts as the eye's outermost lens. It functions like a window that controls and focuses the entry of light into the eye. The cornea contributes between 65-75 percent of the eye's total focusing power. For you to see clearly, light rays must be focused by the cornea and lens to fall precisely on the retina. The cornea also serves as a filter, screening out some of the most damaging ultraviolet (UV) wavelengths in sunlight. Without this protection, the lens and the retina would be highly susceptible to injury from UV radiation.