Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) progressive external ophthalmoplegia ?
    ### Response:
    Progressive external ophthalmoplegia is a condition characterized by weakness of the eye muscles. The condition typically appears in adults between ages 18 and 40. The most common signs and symptoms of progressive external ophthalmoplegia are drooping eyelids (ptosis), which can affect one or both eyelids, and weakness or paralysis of the muscles that move the eye (ophthalmoplegia).
    