Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Meesmann corneal dystrophy ?
    ### Response:
    Meesmann corneal dystrophy is an eye disease that affects the cornea, which is the clear front covering of the eye. This condition is characterized by the formation of tiny round cysts in the outermost layer of the cornea, called the corneal epithelium. This part of the cornea acts as a barrier to help prevent foreign materials, such as dust and bacteria, from entering the eye.
    