Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Chronic progressive external ophthalmoplegia ?
    ### Response:
    Chronic progressive external ophthalmoplegia (CPEO) is a condition characterized mainly by a loss of the muscle functions involved in eye and eyelid movement. Signs and symptoms tend to begin in early adulthood and most commonly include weakness or paralysis of the muscles that move the eye (ophthalmoplegia) and drooping of the eyelids (ptosis).
    