Princeton's WordNet(0.00 / 0 votes)Rate this definition: 1  mushroom(noun) common name for an edible agaric (contrasting with the inedible toadstool) 2  mushroom(noun) mushrooms and related fleshy fungi (including toadstools, puffballs, morels, coral fungi, etc.)
A cornea transplant is an operation used to remove all or part of a damaged cornea and replace it with healthy cornea tissue from the eye of a suitable donor. A cornea transplant is an operation used to remove all or part of a damaged cornea and replace it with healthy cornea tissue from the eye of a suitable donor.
Because the cornea is as smooth and clear as glass but is strong and durable, it helps the eye in two ways: It helps to shield the rest of the eye from germs, dust, and other harmful matter. The cornea shares this protective task with the eyelids, the eye socket, tears, and the sclera, or white part of the eye. 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. When light strikes the cornea, it bends -- or refracts -- the incoming light onto the lens.