Looking straight ahead, the upper lid usually hides the top 1-2mm of the cornea. A ptosis is when the upper lid covers more of the cornea and sits in a lower position. An abnormal drooping of the eyelid can be caused by several conditions including:

  • Detachment of the levator muscle (aponeurotic)
  • Disease of the muscle itself (myogenic)
    • eg myotonic dystrophy
  • Problems with the nerve supply to the muscle (neurogenic)
    • eg myasthenia gravis, Horners syndrome, 3rd nerve palsy

Please login or subscribe to view the rest of this page.